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:
A meteoroid becomes a meteorite when it  
 (A) impacts the surface of a planet. (B) encounters the atmosphere of a planet. (C) makes a complete orbit around a planet. (D) starts to burn up in the atmosphere of a planet.

Ex Output:
A


Ex Input:
Which two protein molecules are essential for muscle contraction and relaxation?  
 (A) actin and myosin (B) collagen and tubulin (C) hemoglobin and myoglobin (D) amylase and polymerase

Ex Output:
A


Ex Input:
A student wants to find the relationship between the diameter of several plastic disks and the circumference of each disk. Which of these types of graphs should be constructed to determine this relationship?  
 (A) pie graph (B) line graph (C) scatterplot (D) box-and-whisker plot

Ex Output:

B