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:
Eyeglasses help a nearsighted person see as a result of  
 (A) absorption. (B) diffraction. (C) reflection. (D) refraction.

Ex Output:
D


Ex Input:
In which of these organs does most absorption of nutrients take place?  
 (A) liver (B) stomach (C) small intestine (D) large intestine

Ex Output:
C


Ex Input:
Ella waves good-bye from the bus. What body system pulls on bones to let Ella wave her arm?  
 (A) muscular system (B) nervous system (C) digestive system (D) circulatory system

Ex Output:

A