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.

Example Input: Which two processes occur during the life spans of all animals?  
 (A) hibernation and migration (B) growth and development (C) changing color and shedding fur (D) building nests and communication
Example Output: B

Example Input: Similar types of cells form tissues. What is the next level of complexity formed from the grouping of tissues?  
 (A) organs (B) organelles (C) organisms (D) organ systems
Example Output: A

Example Input: Which tools are needed to measure the length and mass of a seashell?  
 (A) a ruler and a balance (B) a ruler and a microscope (C) a balance and a stopwatch (D) a microscope and a magnet
Example Output:
A