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 Input:
Which would be a safe practice to exercise during laboratory investigations?
(A) using open flames to heat all materials (B) keeping your cell phone on the laboratory countertop (C) knowing where your instructor/laboratory leader is at all times (D) removing your safety glasses when moving from station to station

Ex Output:
C

Ex Input:
A student is investigating which type of soil is best for growing tomato plants from seeds. The student plants four tomato seeds in each of three different containers of soil. Which step of the procedure would help the student get the most reliable results?
(A) Place one container in a dark room. (B) Use different types of tomato seeds. (C) Change only the soil type in each container. (D) Water each container with a different amount of water.

Ex Output:
C

Ex Input:
Specialized cells protect the human body from disease-causing microbes by
(A) producing chemicals that destroy the microbes (B) dissolving wastes from the microbes (C) creating recessive genes in the microbes (D) supplying oxygen and nutrients to the microbes

Ex Output:
A