Which statement about physiological density is accurate?

• A. Physiological density measures people per unit of arable land; higher values indicate more pressure on productive land.
• B. Arithmetic density measures the same as physiological density.
• C. Physiological density measures urban density.
• D. Physiological density is always lower than arithmetic density.

Answer: (A)

Physiological density tells us how many people are supported by a unit of arable land, so it highlights the potential pressure on productive land to produce food. The statement that correctly describes it notes that it’s people per unit of arable land and that higher values indicate more strain on that land to sustain the population. This concept helps explain why some densely populated regions with limited arable land face greater challenges in food production. The other options mix up what is being measured: arithmetic density uses total land area, not just arable land; physiological density does not measure urban density; and physiological density is not always lower than arithmetic density—its value depends on how much arable land there is relative to population.