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]: The Great Ocean Conveyer ocean current system runs north through the Atlantic from the equatorial region. If this current got disrupted, North American and European climates would become  
 (A) rainier. (B) colder. (C) windier. (D) more humid.
[EX A]: B

[EX Q]: Campers shouted toward a canyon wall. What characteristic of sound best explains why the campers heard an echo?  
 (A) Sound waves traveled slowly down the canyon. (B) Sound waves were absorbed by the canyon wall. (C) Sound waves reflected off the canyon wall. (D) Sound waves were refracted around the canyon.
[EX A]: C

[EX Q]: Which of these diseases is caused by a bacterium?  
 (A) rabies (B) influenza (C) strep throat (D) chicken pox
[EX A]:
C