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 Input:
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.

Ex Output:
A


Ex Input:
Which energy source is considered nonrenewable?  
 (A) moving water (B) fossil fuel (C) wind (D) biomass

Ex Output:
B


Ex Input:
On a cold day, a student felt the tires of her bike before riding it to the store. When she arrived at the store, she felt the tires again and noticed that they were warmer. What caused the temperature of the bicycle tires to change?  
 (A) the wind blowing against the tires (B) the air escaping from the spinning tires (C) the rubbing between the ground and the tires (D) the heat transferring from the rider's hands to the tire

Ex Output:

C