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:
Some kinds of fish live most of their lives in salt water but lay their eggs in freshwater. Their ability to survive in different environments is an example of  
 (A) adaptation (B) developmental stages (C) a habit (D) selective breeding

Ex Output:
A


Ex Input:
You wish to closely observe a small insect. Which tool is the best to use?  
 (A) a balance (B) a test tube (C) a telescope (D) a magnifying glass

Ex Output:
D


Ex Input:
Which safety measure should a student take when handling a microscope?  
 (A) clean the lenses with your fingers (B) keep switching the magnifications (C) carry the microscope with two hands at all times (D) make sure to put the microscope on an uneven surface

Ex Output:

C