A Plain Vanilla Interest-Rate Swap Is an Agreement to Exchange

A plain vanilla interest-rate swap is an agreement to exchange a series of periodic payments, one computed at a fixed rate and the other at

A) A floating rate indexed to a money-market rate in the same currency (e.g., Libor) .
B) A floating rate linked to the return on any financial index, e.g., an equity index.
C) A floating rate indexed to a money-market rate in the same or a different currency.
D) A floating rate indexed to a commodity (e.g., gold) price.