Given a text T, and several options, according to the question posed in the text T to choose the most appropriate option from the options as the answer, please directly output the most appropriate option, do not need to output the explanation.

Which of the following statements about exchange-traded funds is most correct?
Option A:Exchange-traded funds are not backed by any assets.
Option B:The investment companies that create exchange-traded funds are financial intermediaries.
Option C:The transaction costs of trading shares of exchange-traded funds are substantially greater than the combined costs of trading the underlying assets of the fund.

Answer: B