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.

Input: Consider Input: The most significant human-induced impact on Earth's atmosphere comes from the use of which energy resource?  
 (A) flowing water (B) fossil fuels (C) sunlight (D) winds

Output: B


Input: Consider Input: A student hypothesizes that algae are producers. Which question will best help the student determine if this is correct?  
 (A) Do algae consume other organisms? (B) Which organisms consume algae? (C) Do algae use sunlight to make food? (D) Could an ecosystem survive without algae?

Output: C


Input: Consider Input: Many years ago, purple dye was made from some sea animals. Then, in 1856, William Perkins tried to make a new medicine. Instead, he found a way to make purple dye from coal. What is a positive effect of his discovery?  
 (A) Some diseases can be treated. (B) Purple clothing can be made. (C) Sea animals are not needed to make purple dye. (D) Perkins is famous for discovering a new medicine.


Output: C