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.

Input: Consider Input: A drug company developed a pill to reduce cases of stomach virus. To test the medication, half of the participants got the pill with the new medicine and half got a sugar pill. Which term best identifies the participants who got a sugar pill?  
 (A) control (B) experimental (C) dependent variable (D) independent variable

Output: A


Input: Consider Input: What happens to the water vapor in an air mass as it ascends?  
 (A) It freezes. (B) It condenses. (C) It vaporizes. (D) It polarizes.

Output: B


Input: Consider Input: Which of these objects is visible because it reflects light toward the eye?  
 (A) burning candle (B) flashlight bulb (C) glowing campfire log (D) shiny metallic balloon


Output: D