TASK DEFINITION: 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.
PROBLEM: 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

SOLUTION: A

PROBLEM: Which of the following is the most likely cause of earthquakes?  
 (A) shifting rock layers (B) crashing meteorites (C) rotation of the core (D) magnetic force

SOLUTION: A

PROBLEM: Prairie dogs can run very quickly. This adaptation enables the prairie dog to  
 (A) attract mates. (B) intimidate predators. (C) escape from predators. (D) chase after their young.

SOLUTION:
C