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 is the best tool for measuring the temperature of lake water?  
 (A) Meter stick (B) Balance (C) Graduated cylinder (D) Thermometer
[EX A]: D

[EX Q]: The main function of a fish's fins is to help the fish  
 (A) reproduce (B) see (C) breathe (D) move
[EX A]: D

[EX Q]: Stars form from nebulae of dust and gases. Depending on its properties, a star may become a red, yellow, white, or blue star. Which property determines this star type?  
 (A) age (B) location (C) mass (D) shape
[EX A]:
C