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:
All of the following can become fossils except  
 (A) bones. (B) shells. (C) teeth. (D) rocks.

Ex Output:
D


Ex Input:
Which best explains how nutrients get into soil?  
 (A) through exposure to air (B) by absorbing sunlight (C) through decaying matter (D) by rocks eroding

Ex Output:
C


Ex Input:
A ship has a satellite communication device to identify the ship's position at sea. For which of the following activities is this device most likely used?  
 (A) control (B) guidance (C) propulsion (D) suspension

Ex Output:

B