Instructions: You are given a science question (hard-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.
Input: Garden plants on Earth require four resources to stay alive: soil, air, water, and sunlight. How many of these resources are necessary for life to exist on the moon or another planet?  
 (A) 4 (B) 3 (C) 2 (D) 1
Output:
A