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]: 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
[EX A]: A

[EX Q]: How do traits of animals such as ear shape, nose shape, and hair color most often get passed to offspring?
(A) sexual reproduction (B) asexual reproduction (C) adaptation (D) instinct
[EX A]: A

[EX Q]: A student has recorded rainfall amounts for 28 days and uses a calculator to determine the total rainfall. What does the student calculate when she divides the total rainfall by 28?
(A) mean rainfall (B) rainfall mode (C) median rainfall (D) percentage of rainfall
[EX A]:
A