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: Which of these is evidence for the theory of plate tectonics?  
 (A) the melting of the polar ice caps (B) the shifting of biomes as climates change (C) the prevalence of granite on all the continents (D) the presence of volcanoes around the Pacific rim
Output:
D