Which term describes the minimum population size required to sustain a service?

• A. Range
• B. Central Place Theory
• C. Threshold
• D. Public Services

Answer: (C)

The main idea is the threshold. In urban geography, threshold is the minimum number of people needed to support a service so it can operate profitably and stay in business. If the local population (and potential customers) is large enough, the service can cover its costs and continue to serve the area; if not, the service may not open or will close because demand is too low. This concept helps explain why certain services exist only in larger towns or cities while others can survive in smaller communities.

Range, by contrast, is about how far people are willing to travel to reach a service, not how many people are required to sustain it. Central Place Theory deals with the spatial arrangement and sizes of settlements and the distribution of services in a region, not specifically the minimum population needed. Public Services is a broad term for government-provided services and doesn’t describe the population threshold for viability.