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]: Which of the following is the main role of flowers found on most flowering plants?  
 (A) to take in air (B) to produce seeds (C) to absorb nutrients (D) to protect the stem
[EX A]: B

[EX Q]: The Sun is classified as  
 (A) an organism (B) a decomposer (C) a star (D) a planet
[EX A]: C

[EX Q]: James placed a breath mint and a lump of toothpaste in a cup of water and let it sit overnight. Which statement best explains why the breath mint was gone the following morning, but the toothpaste was still at the bottom of the cup?  
 (A) The breath mint was less soluble than the toothpaste. (B) The breath mint was more soluble than the toothpaste. (C) The breath mint had a lower density than the toothpaste. (D) The breath mint had a greater density than the toothpaste.
[EX A]:
B