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:
When pressure is released along a fault line, the energy produced spreads as mechanical waves in the form of an earthquake. The mechanical waves transferred to the air become
(A) sound. (B) electricity. (C) light. (D) heat.

Ex Output:
A

Ex Input:
Which of these would help to prevent infections from occurring in small cuts and scrapes?
(A) apply a cold ice pack (B) raise the injured area (C) apply pressure to stop bleeding (D) wash the area with warm, soapy water

Ex Output:
D

Ex Input:
Atoms of the same element can have different atomic masses because they can have different numbers of
(A) neutrons. (B) protons. (C) electrons. (D) neutrinos.

Ex Output:
A