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 unit is used to indicate the amount of energy in food?  
 (A) ounce (B) degree (C) calorie (D) gram
[EX A]: C

[EX Q]: A star is a large astronomical body that  
 (A) reflects light. (B) condenses light. (C) emits light. (D) absorbs light.
[EX A]: C

[EX Q]: Which of the following is the most basic need for a plant?  
 (A) shade (B) heat (C) water (D) sand
[EX A]:
C