You might keep your money in a bank, but have you heard of a time bank? This online service allows users to trade services with one another without exchanging money. For example, a hairdresser gives someone a haircut for one hour of credit in the time bank. The hairdresser could then use that credit to have a plumber come work for her for an hour. Time banks are useful for people who cant arrange direct trades. The plumber might not want a haircut, but he can work for the hairdresser and earn credit to use with someone else. How does the detail "The plumber might not want a haircut, but he can work for the hairdresser and earn credit to use with someone else" best support the central idea that time banks are a convenient way to get things done? O A. It gives an example to show how time banks work even for those who are not able to arrange a one-to-one trade. B. It confirms the stereotype that plumbers are not usually interested in improving their appearances. O C. It reminds the reader that the Internet makes it easy for people to find others who have gone through similar life experiences. D. It suggests that many users would prefer to trade services rather than pay cash for something that is not an absolute necessity.