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: Some marine organisms living deep in the ocean can produce their own light. The light they produce is most likely used for which of these activities?  
 (A) moving through the water (B) producing oxygen (C) attracting prey (D) escaping predators
Output:
C