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: On a field trip, a student holds a frog and reports that it has slippery skin. This is an example of  
 (A) a measurement (B) a prediction (C) an explanation (D) an observation

Output: D


Input: Consider Input: As Earth revolves around the Sun, the number of daylight hours varies from place to place. In which location would the number of daylight hours remain constant?  
 (A) North Pole (B) Prime Meridian (C) Equator (D) Antarctica

Output: C


Input: Consider Input: A student removed a wool hat from her head. Her hair stood up from static electricity. What did her hat do to cause this?  
 (A) gave her hair a neutral charge (B) removed protons from her hair (C) gave her hair a negative charge (D) removed electrons from her hair


Output: D