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:
Claudia's teacher places a photograph of an organism on the board. He asks Claudia to determine if the organism is a plant or an animal. The answer to which question will best help Claudia determine if the organism is a plant or an animal?  
 (A) Does the organism have cells? (B) Does the organism reproduce? (C) Does the organism live in the forest? (D) Does the organism make its own food?

Ex Output:
D


Ex Input:
Which of these occurs if myosin fails to bind to actin during muscle contraction?  
 (A) The muscle cells will lose ATP. (B) The muscle cells will remain relaxed. (C) The muscle cells will produce lactic acid. (D) The muscle cells will lose calcium ions.

Ex Output:
B


Ex Input:
A student plans to conduct an experiment to see how quickly mice learn to navigate a maze to reach a reward at the other end. Which of these will help lead to the most accurate conclusion?  
 (A) make the maze bigger (B) provide different food rewards (C) use a reward other than food (D) use the same maze and reward each day

Ex Output:

D