问题如下：
Which of the following statements about exchange-traded funds is most correct?
选项：
A. Exchange-traded funds are not backed by any assets.
B. The investment companies that create exchange-traded funds are financial intermediaries.
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.
解释：
B is correct.
The investment companies that create exchange-traded funds (ETFs) are financial intermediaries. ETFs are securities that represent ownership in the assets held by the fund. The transaction costs of trading shares of ETFs are substantially lower than the combined costs of trading the underlying assets of the ETF.
可以翻译一下C选项吗？没看明白C选项表达的是什么。