Given that a seasoned 360-month agency mortgage pass-through security has currently a weighted average maturity (WAM) of 357 months. It has $400M outstanding balance, a 7.5% pass-through coupon rate, and 8.125% weighted average coupon (WAC). Assuming 125% PSA and a first month mortgage payment of $2,975,868, what is the expected prepayment for the first month?

Group of answer choices

$267,535

$267,470

$334,473

$334,647

None of the above