P (Urban Sprawl) signifies the outward expansion of cities into rural areas, typically marked by low-density construction. This corresponds to P–4.
Q (Smart Growth) focuses on consolidating development within dense, pedestrian-friendly urban cores to enhance health and the environment. This corresponds to Q–3.
R (Greenfield Development) denotes construction on land that has not been previously developed. This corresponds to R–2.
S (Brownfield Development) involves the reuse of land previously used for other purposes, frequently leading to alterations in land use and cover. This corresponds to S–1.
Therefore, the accurate pairing is (C) P–4, Q–3, R–2, S–1.