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 is the MAJOR reason Earth has seasons?
(A) Earth has a moon (B) Earth has a tilted axis (C) Earth has a magnetic field (D) Earth has an elliptical orbit
Example Output: B

Example Input: One type of animal hatches from an egg, breathes through gills when it is young, and mainly lives on land as an adult. Into which group is this animal classified?
(A) amphibians (B) birds (C) mammals (D) reptiles
Example Output: A

Example Input: A student wants to compare the masses and volumes of three marbles. Which two instruments should be used?
(A) Balance and graduated cylinder (B) Centimeter ruler and thermometer (C) Graduated cylinder and centimeter ruler (D) Thermometer and balance
Example Output:
A