instruction:
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 is an example of a chemical reaction?  
 (A) Vinegar added to baking soda forms a gas. (B) Water evaporates into air. (C) Sugar dissolves in water. (D) Corn kernels are crushed to form flour.
answer:
A


question:
Which of the following compounds is most likely to be part of living organisms?  
 (A) C?H??O? (B) BF? (C) MoCl? (D) CsI
answer:
A


question:
Which of these best defines the term "pollutant"?  
 (A) anything humans add to the atmosphere and oceans (B) any substance that is harmful to the environment (C) any substance that is a waste product of industry (D) a substance that does not break down over time
answer:

B