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: Some scientists believe that the mass extinction of dinosaurs was caused by the impact of a large meteorite on Earth. This impact would have caused a darkening of the sky due to dust blown into the upper atmosphere. This darkening would have reduced the sizes of some ecosystems because of  
 (A) longer seasons. (B) accelerated erosion. (C) reduced photosynthesis. (D) increased number of hurricanes.
Example Output: C

Example Input: Which occurs as a result of Earth's tilt on its rotating axis?  
 (A) movement of the tides (B) prevalent or trade winds (C) seasonal changes in the climate (D) light and dark changes of day and night
Example Output: C

Example Input: Which is a function of the cardiovascular system?  
 (A) to move water throughout the body (B) to provide structural support for the body (C) to eliminate waste from the body (D) to transport gases throughout the body
Example Output:
D