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 form of energy is found in food?  
 (A) chemical (B) electrical (C) sound (D) mechanical

Ex Output:
A


Ex Input:
The changing appearances of the nighttime sky over the surface of Earth and eclipses of the Moon have provided evidence that  
 (A) Earth is a sphere. (B) Earth supports life. (C) Earth has a layered atmosphere. (D) Earth is covered mostly with water.

Ex Output:
A


Ex Input:
Which of these best describes the function of the skeletal system?  
 (A) transports oxygen and nutrients throughout the body (B) supports and protects tissues and organs (C) removes harmful wastes from the cells of the body (D) breaks down food into a form that cells can use

Ex Output:

B