Given the task definition and input, reply with output. 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.

Company X makes 100 custom buses each year. Company Y makes 10,000 of one type of bus each year. Which of the following is the most likely reason a customer would buy a bus from company X instead of company Y?
(A) to keep the cost of the bus low (B) to ensure that the bus will be easy to replace (C) to provide ideas about how the bus will be built (D) to ensure that people know how to drive the bus
C