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:
An enclosed 20 mL metal cylinder was filled with a gas sample at room temperature. The sample then was transferred to an empty 40 mL enclosed container, also at room temperature. After being transferred, the volume of the gas was  
 (A) 10 mL. (B) 20 mL. (C) 30 mL. (D) 40 mL.

Ex Output:
D


Ex Input:
Which two things interact most in the water cycle?  
 (A) oceans and the Moon (B) oceans and the Sun (C) lakes and the Moon (D) lakes and the Sun

Ex Output:
B


Ex Input:
In order to record the passing of a distant comet, which instruments would be the most useful?  
 (A) camera, tripod, and telescope (B) telescope, binoculars, and camera (C) camera with flash attachment, and tripod (D) telescope with camera attachment and camera

Ex Output:

D