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 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:
Which is the best tool for measuring the temperature of lake water?  
 (A) Meter stick (B) Balance (C) Graduated cylinder (D) Thermometer

Ex Output:
D


Ex Input:
To compare the hardness of different minerals, it would be BEST to find  
 (A) the color of the minerals. (B) which minerals scratch other minerals. (C) which minerals reflect light most strongly. (D) the samples that feel smoothest to the touch.

Ex Output:

B