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: A bright object with a long tail of glowing gases is in orbit around the Sun. This object is most likely  
 (A) a planet (B) a star (C) an asteroid (D) a comet

SOLUTION: D

PROBLEM: Calcium carbonate (CaCO_{3}) is considered a compound because it is made up of two or more  
 (A) molecules. (B) elements. (C) gases. (D) solids.

SOLUTION: B

PROBLEM: What type of rock was the fossil most likely found in?  
 (A) igneous (B) volcanic (C) sedimentary (D) metamorphic

SOLUTION:
C