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: What are produced in both the male and female reproductive systems in humans?
(A) sperm (B) nutrients (C) fertilized eggs (D) sex cells
Example Output: D

Example Input: A meteoroid becomes a meteorite when it
(A) impacts the surface of a planet. (B) encounters the atmosphere of a planet. (C) makes a complete orbit around a planet. (D) starts to burn up in the atmosphere of a planet.
Example Output: A

Example Input: Which of the following activities is the best example of instinctive behavior in an animal?
(A) A dog sits when told to sit by its owner. (B) A bird avoids an insect that has a bad taste. (C) A newly hatched sea turtle walks toward the ocean. (D) A chimpanzee uses a stick to pull termites from a tree stump.
Example Output:
C