Which option gives the correct benefit of studying climatic controls?

Correct answer: Understanding causes of climatic differences among regions

Direct answer: Option A is correct. Climatic controls are the factors that influence the climate of a place, such as latitude, altitude, distance from the sea, winds, pressure, relief and ocean currents. Studying them helps us understand why two regions can have different temperature or rainfall. The reasoning is: identify the controls, observe how they affect a region, and then explain regional climatic variation. Option A is correct because it gives the real geographical benefit: finding the causes of differences between regions. Option B is wrong because counting city population belongs to demography, not climatic controls. Option C is wrong because one day’s condition is weather, whereas climate is the long-term pattern. Option D is wrong because river length is not changed by studying climate controls. Memory cue: climate controls explain “why places differ.”