Which of the following is the best definition of a mortgage-backed security (MBS)?

Group of answer choices A zero-coupon bond where the cash flows come from a single mortgage loan similar to a Treasury STRIP A bond where the cash flows are guaranteed by Freddie Mac and Fannie Mae. A bond where the cash flows are based on the mortgage interest rate offered by an average of retail banks. A bond where the cash flows are based on payments made to banks on mortgage loans backing the bond issue.