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]: Diseases that can be transmitted between organisms are  
 (A) infectious. (B) inherited. (C) environmental. (D) congenital.
[EX A]: A

[EX Q]: 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
[EX A]: A

[EX Q]: Scientists use different tools during their investigations. What tool does a scientist use to study cells?  
 (A) a balance (B) a microscope (C) a centimeter ruler (D) a graduated cylinder
[EX A]:
B