31. Which of the following is NOT an advantage of having an interest rate swap market? A. As it is generally liquid, it benefits both borrowers and lenders. B. As most swaps involve banks, their credit departments can carry out credit assessments more easily than potential lenders. C. As the banks are involved in most swaps, banks require a spread between the two interest rates. D. Swaps enable companies to carry out regulatory and tax arbitrage.

why c is not correct??