Doubt in RC option C

Passage - Urban ecologists have long noted an institutional paradox at the heart of conservation science: the environments most proximate to human habitation receive the least systematic attention. Cities, which now house more than half the world's population and are expanding at rates that make them the defining ecological frontier of this century, are still treated by most conservation funding bodies as ecological dead zones — places from which nature has retreated and to which it cannot meaningfully return. The persistence of this view, despite mounting evidence to the contrary, reflects not an objective reading of ecological data but a conceptual legacy that ties conservation value to wildness and distance from human activity. The most direct counter-argument is climatic. Urban tree canopy, even in fragmented form, functions as a measurable thermal regulator. Studies of mid-sized cities across temperate zones have found that neighbourhoods with thirty per cent or greater canopy cover record peak summer temperatures three to four degrees lower than adjacent unplanted districts, reducing cooling energy demand and associated emissions. When the cost of establishing and maintaining this cover is set against the cost of equivalent emissions reduction through remote reforestation — accounting for time to canopy maturity and the logistical overheads of remote site management — urban planting frequently delivers comparable outcomes at lower cost per tonne of carbon moderated. Yet conservation budgets in most countries allocate less than four per cent of their funds to urban greening initiatives. Ecological function, however, extends beyond climate. Urban green corridors — interconnected strips of vegetation threading through residential and commercial zones — have been shown to sustain pollinator populations at densities capable of servicing agricultural areas extending to forty kilometres from the urban edge. For cities surrounded by horticultural and smallholder farming zones, this is not a peripheral benefit: it is a direct input to food production. The argument that urban ecology is inherently disconnected from the productive landscape collapses when mapped against the actual spatial relationship between city boundaries and the farms they adjoin. The case for urban wetlands and permeable green surfaces is perhaps the most quantitatively compelling. Engineering analyses of municipal drainage in flood-prone cities have found that the integration of green roofs, bioswales, and retained urban wetland areas reduces peak stormwater runoff by between thirty and fifty per cent, lowering the capital expenditure required for conventional pipe-and-retention infrastructure by a factor that frequently exceeds three. These figures are not marginal. They represent a structural shift in the cost calculus of urban water management. That they have not prompted a corresponding shift in conservation funding priorities suggests that the boundaries between "conservation" and "infrastructure" policy have calcified in ways that serve neither discipline. The institutional reluctance to treat urban green spaces as primary conservation assets is, in this respect, a policy failure with measurable ecological costs. The framing of cities as spaces of ecological deficit — zones requiring remediation rather than recognition — has directed conservation investment away from environments where the return on ecological function per unit of expenditure may be highest. Repositioning urban green infrastructure within the mainstream conservation accounting framework is not a concession to urban sentiment. It is a correction demanded by the evidence. Question - Based on the passage, which one of the following scenarios would most strongly support the author's case for repositioning urban green infrastructure within mainstream conservation funding? C) A city in a major agricultural region maintains a network of vegetated green corridors running from its urban parks into the surrounding smallholder farming zones, and ecological monitoring of these corridors confirms that pollinator populations resident in the urban green spaces are directly supporting crop yields on farms up to forty kilometres from the city boundary. D) An urban drainage authority integrates bioswales and retained wetland areas across three flood-prone city districts and records a forty-two per cent reduction in peak stormwater runoff, with engineering cost analysis showing the green infrastructure saves the city more than three times what equivalent conventional pipe-and-retention works would have cost. My answer is D. I eliminated option C as it says "green corridors running from its urban parks into the surrounding smallholder farming zones". Passage mentions (P3) "vegetation threading through residential and commercial zones", the benefit of vegetation goes as far as farming zones, but no where it's mentioned that vegetation goes as far as farming zones.