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 Input:
Which unit is used to express the amount of energy in food?  
 (A) Calorie (B) degree Celsius (C) milliliter (D) gram

Ex Output:
A


Ex Input:
In an accurate diagram of the solar system, which object would be shown closest to Earth?  
 (A) the Moon (B) the asteroid belt (C) Mars (D) Saturn

Ex Output:
A


Ex Input:
Which property of water can cause a rock to break apart?  
 (A) Water boiling at 100°C. (B) Water losing energy slowly. (C) Water expanding as it freezes. (D) Water having a high surface tension.

Ex Output:

C