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:
One method of heat distribution is a baseboard forced hot water system. A baseboard system carries hot water through a pipe that passes through many small, flat plates called fins. What is the purpose of these fins?  
 (A) to dissipate the heat of the hot water flowing through the pipe (B) to prevent the baseboard from coming in contact with hot surfaces (C) to replace the heated air leaving the system with cold air (D) to prevent dust and other particles from entering the baseboard

Ex Output:
A


Ex Input:
Which is a way the agricultural biotechnology industry could have a positive impact on the environment?  
 (A) by producing crops that are virus resistant (B) by making robots to replace large farm machines (C) by reducing the need for countries to import food (D) by increasing the use of wind farms that produce electricity

Ex Output:
C


Ex Input:
When you are riding a bicycle at night, your bicycle's reflectors help people in cars see your bicycle. How do bicycle reflectors work?  
 (A) They are made of a special material that gives off its own light. (B) They are hooked up to batteries that allow them to produce light. (C) They bounce light back from other sources. (D) They are covered with paint that glows in the dark.

Ex Output:

C