TASK DEFINITION: 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.
PROBLEM: In 1971, the bones of an extinct flying dinosaur were discovered. This kind of discovery helps everyone learn more about
(A) impact of humans on Earth. (B) effect of gravity on animals. (C) history of animal species on Earth. (D) likelihood that dinosaurs will reappear.

SOLUTION: C

PROBLEM: What determines how long the Moon takes to complete one cycle of phases?
(A) the period of rotation of the Moon around its axis (B) the period of revolution of the Moon around Earth (C) the period of rotation of Earth around its axis (D) the period of revolution of Earth around the Sun

SOLUTION: B

PROBLEM: The greatest amount of diversity can be found among which type of organism?
(A) plants (B) animals (C) bacteria (D) fungi

SOLUTION:
C