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.
--------
Question: 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

Answer: B


Question: Which unit is used to express the amount of energy in food?  
 (A) Calorie (B) degree Celsius (C) milliliter (D) gram

Answer: A


Question: In 1931, Barbara McClintock discovered that genes could change position on a chromosome. In corn plants, if a certain gene was moved next to the gene that controls kernel color, the kernels in an ear of corn were various colors. Which statement best supports McClintock's discovery?  
 (A) Genes control inherited traits in organisms. (B) Corn plants can reproduce in laboratory environments. (C) Chromosomes can move around in the nucleus of a cell. (D) Genes are able to disappear and reappear in later generations.

Answer:
A