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 of the following is most consistent with the modern theory of evolution?  
 (A) Parents pass their physical traits to their offspring; those offspring with traits that help them survive in the environment are able to reproduce. (B) Parents change their physical traits in order to survive in the environment, then those parental traits are passed to their offspring. (C) Life on this planet came from another planet far out in space. (D) Living organisms have not changed for hundreds of millions of years.

Ex Output:
A


Ex Input:
Which force produces energy as heat?  
 (A) pull (B) gravity (C) friction (D) magnetic

Ex Output:
C


Ex Input:
Which characteristic of an element determines its placement in the periodic table?  
 (A) mass (B) size (C) number of neutrons (D) number of protons

Ex Output:

D