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:
How does sedimentary rock form?  
 (A) sediments cool (B) sediments melt (C) sediments separate (D) sediments compress

Ex Output:
D


Ex Input:
In order to maintain good health, humans should  
 (A) eat foods high in fat (B) exercise regularly (C) drink alcohol often (D) smoke tobacco occasionally

Ex Output:
B


Ex Input:
In a container, a mixture of water and salt is stirred so that the salt dissolves completely. Sand is added to this solution and allowed to settle to the bottom of the container. If the container is placed on a heat source and the liquid evaporates completely, what will be left in the container?  
 (A) Nothing will remain in the container. (B) Only salt will remain in the container. (C) Only sand will remain in the container. (D) Salt and sand will both remain in the container.

Ex Output:

D