Teacher: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.
Teacher: Now, understand the problem? Solve this instance: The theory of plate tectonics provides the current explanation for the way in which  
 (A) stars change. (B) continents move. (C) rocks are formed. (D) tides are produced.
Student:
B