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.

Input: Consider Input: Which type of air mass forms over the ocean near the equator?  
 (A) moist and warm (B) moist and cool (C) dry and warm (D) dry and cool

Output: A


Input: Consider Input: If the solar system were used as a model of an atom, what would the Sun most likely represent?  
 (A) an ion (B) a nucleus (C) a neutron (D) an electron

Output: B


Input: Consider Input: Why are some rocks smoother and rounder than others?  
 (A) They have the shapes of the minerals from which they are made. (B) They were smoothed by the action of wind and water. (C) They were squeezed up through the soil. (D) They hardened in rounded pockets of soil.


Output: B