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:
A star is a large astronomical body that
(A) reflects light. (B) condenses light. (C) emits light. (D) absorbs light.

Ex Output:
C

Ex Input:
Which characteristic of sound makes it possible for bats to fly in the dark without hitting any objects?
(A) refraction (B) reflection (C) conduction (D) amplification

Ex Output:
B

Ex Input:
Ocean currents, like the Gulf Stream, affect world climate by
(A) spreading plant and animal life over a wider area. (B) ensuring ocean density is not the same globally. (C) carrying sediment from rivers and inland basins. (D) transferring heat to and from various regions.

Ex Output:
D