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]: How do most fish get the oxygen they need to survive?  
 (A) They take in water and break it down into hydrogen and oxygen. (B) Using their gills, they take in oxygen that is dissolved in water. (C) They get their oxygen from the food they eat. (D) They come to the surface every few minutes to breathe air into their lungs.
[EX A]: B

[EX Q]: Which two processes occur during the life spans of all animals?  
 (A) hibernation and migration (B) growth and development (C) changing color and shedding fur (D) building nests and communication
[EX A]: B

[EX Q]: Which of these statements is true about the parts that make up the atom?  
 (A) Protons are larger than neutrons. (B) Electrons have a positive charge. (C) Electrons are inside the nucleus. (D) Neutrons have no charge.
[EX A]:
D