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.

Input: Consider Input: Plants growing in a pond release a gas that fish need to survive. Which gas do the plants release that fish use?  
 (A) helium (B) hydrogen (C) nitrogen (D) oxygen

Output: D


Input: Consider Input: A student measured liquid with a graduated cylinder. Which of the following units could be used to record the volume of the liquid?  
 (A) pounds (B) meters (C) grams (D) milliliters

Output: D


Input: Consider Input: Immediately before and after running a 50 metre race, your pulse and breathing rates are taken. What changes would you expect to find?  
 (A) no change in pulse but a decrease in breathing rate (B) an increase in pulse but no change in breathing rate (C) an increase in pulse and breathing rate (D) a decrease in pulse and breathing rate (E) no change in either


Output: C