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.

Example Input: Electron transport in mitochondria results in a chemiosmotic gradient of which particle across the mitochondrial membrane?
(A) ADP (B) ATP (C) protons (D) neutrons
Example Output: C

Example Input: Martin is writing a report for science class about how the tilt of Earth affects living organisms. Which subject should Martin include in his report that is directly affected by Earth's tilt?
(A) night and day (B) cloud formation (C) phases of the Moon (D) changing of the seasons
Example Output: D

Example Input: Some types of trees are able to survive the heat of a forest fire. Which of the following characteristics would best help a tree survive a fire?
(A) large leaves (B) shallow roots (C) thick bark (D) thin trunks
Example Output:
C