Which pair correctly shows climatic control and effect?

Correct answer: Altitude causing temperature decrease

The direct answer is A: altitude causes temperature to decrease. Altitude means height above sea level. In the lower atmosphere, air pressure generally decreases with height, and rising air expands and cools; therefore high places are commonly cooler than nearby lowlands. Step by step: compare a lowland with a mountain location, note that the mountain location is at greater altitude, understand that air is generally cooler higher up, and conclude that altitude can explain the lower temperature. Option A is correct because it pairs a real climatic control with its usual effect. Option B is wrong here: an ocean current can influence coastal climates, but it is not the stated general relationship and does not explain this pair. Option C is not a control-effect statement; a rain shadow describes reduced rainfall behind a mountain, not altitude causing temperature decrease. Option D is unrelated: language does not control temperature or rainfall. Memory cue: as altitude rises, temperature generally falls.