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.

The "Ring of Fire" is a long chain of volcanoes that encircles the Pacific Ocean. Which of the following is the best explanation for the arrangement of these volcanoes?  
 (A) They outline the crater caused by the impact of an asteroid. (B) They follow the shape of the adjacent tectonic plates under the sea. (C) One volcano usually triggers a second volcano with its hot magma. (D) Volcanoes always form in rings because of underwater convection currents.
B