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.

[EX Q]: Rocks that contain fragments of bones, shells, and plant remains are most likely  
 (A) crystals. (B) igneous. (C) sedimentary. (D) metamorphic.
[EX A]: C

[EX Q]: You wish to closely observe a small insect. Which tool is the best to use?  
 (A) a balance (B) a test tube (C) a telescope (D) a magnifying glass
[EX A]: D

[EX Q]: Two samples of gold must have the same  
 (A) mass. (B) volume. (C) length. (D) density.
[EX A]:
D