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: What are produced in both the male and female reproductive systems in humans?  
 (A) sperm (B) nutrients (C) fertilized eggs (D) sex cells
Example Output: D

Example Input: Which statement about plant and animals cells is true?  
 (A) Both have a cell wall to give them support. (B) Both have a large vacuole to store water. (C) Both use mitochondria to produce energy. (D) Both use chloroplasts to store energy.
Example Output: C

Example Input: Which best describes the function of the small intestine?  
 (A) oxygenation of tissue (B) excretion of toxic wastes (C) transportation of blood cells (D) digestion and absorption of food
Example Output:
D