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:
Sal is looking at a map of Massachusetts. He has measured the distance, in inches, from Boston to Salem on the map. He wants to know how many actual miles the inches represent. What feature of the map should he look for?
(A) key (B) scale (C) legend (D) compass

Ex Output:
B

Ex Input:
When oxygen combines with hydrogen, which substance is formed?
(A) water (B) vinegar (C) hydrochloric acid (D) hydrogen dioxide

Ex Output:
A

Ex Input:
Water that evaporates from lakes and streams condenses into clouds and later falls as rain. The property of water that is demonstrated is the ability to
(A) act as a universal solvent. (B) change from a liquid to a gas. (C) boil at a high temperature. (D) absorb large amounts of energy.

Ex Output:
B