Question on Interbank rate and Central Bank Fund rate

I was practicing on the Schweser Qbank and got wrong on this question

The interest rate on excess reserves borrowed by one bank from another bank is most accurately described as a(n):

A) interbank lending rate. B) reserve swap rate. C) central bank funds rate. C is the correct answer. However, I thought bank borrow funds from another bank would be interbank lending rate. Can someone explain why the answer is not A but C. Thank you

Well, I believe it should also be A as it indicates a transaction between two (commercials) banks.

Anyone?