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 describes a specific characteristic necessary for survival in the desert?
(A) conserving water (B) hiding from predators (C) hibernating for long periods (D) producing many offspring
Example Output: A

Example Input: The cells of a plant help the plant maintain its life functions. What part of a plant cell has the function of producing sugar in the presence of sunlight?
(A) chloroplast (B) cytoplasm (C) mitochondria (D) nucleus
Example Output: A

Example Input: What is the source of the organic matter needed for most fertile soils?
(A) moving water (B) eroded sand (C) decaying plants (D) weathered bedrock
Example Output:
C