TASK DEFINITION: You are given a science question (easy-level) and four answer options (associated with "A", "B", "C", "D"). Your task is to find the correct answer based on scientific facts, knowledge, and reasoning. Do not generate anything else apart from one of the following characters: 'A', 'B, 'C', 'D'. There is only one correct answer for each question.
PROBLEM: The transfer of heat in the atmosphere by winds that circulate between the equator and the poles is an example of  
 (A) radiation. (B) insulation. (C) convection. (D) conduction.

SOLUTION: C

PROBLEM: What is a main feature of plains?  
 (A) a flat, level surface (B) a high, steep peak (C) a low, shallow basin (D) a gentle, gradual slope

SOLUTION: A

PROBLEM: What is the major cause of seasonal changes?  
 (A) tilt of the Earth's axis (B) Earth changing its distance from the Sun (C) changing patterns in wind and ocean currents (D) cycles in the amount of energy released by the Sun

SOLUTION:
A