You are given a science question (hard-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.

[EX Q]: Which characteristic property indicates that igneous rock cools slowly?  
 (A) mineral composition (B) hardness (C) density (D) crystal size
[EX A]: D

[EX Q]: In the 17th century, Galileo proposed a hypothesis to explain how suction pumps work. Galileo's hypothesis was disproved, but later it helped Torricelli in the development of an instrument for measuring atmospheric pressure. How did Galileo's hypothesis most likely help with the development of this new technology?  
 (A) by leading Galileo to design a different technology (B) by allowing another scientist to critique Galileo's hypothesis (C) by providing evidence of the effects of atmospheric pressure (D) by inspiring another scientist to test an alternative hypothesis
[EX A]: D

[EX Q]: Why is it winter in North America when it is summer in South America?  
 (A) The south is always warmer than the north. (B) There is less land than water in the south. (C) North America receives less direct sunlight during the winter. (D) When it is December in North America, it is June in South America.
[EX A]:
C