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.

[EX Q]: After playing outside on a cold day, Jaime went inside to wash his hands. Although the water was normal temperature, he noticed that it felt warmer than usual. What would explain this phenomenon?  
 (A) His body had more kinetic energy than the water. (B) Heat flowed from a cooler substance to a warmer substance. (C) The water from the faucet had a higher temperature than his skin. (D) The thermal energy in the room was higher than the thermal energy outside.
[EX A]: C

[EX Q]: Which of the following best represents one particular stage in a life cycle?  
 (A) a fish swimming (B) a seed sprouting (C) a leaf growing (D) a dog eating
[EX A]: B

[EX Q]: Many scientists are convinced that an increase of certain gases in the atmosphere is affecting global temperatures. What makes this hypothesis difficult to prove?  
 (A) Trees absorb these gases. (B) Global temperatures are rising. (C) Many variables affect global temperatures. (D) Many human activities produce these gases.
[EX A]:
C