4. (20 points) You set up a RBMC and lasue a CMBS based on a pool of commercial loans. All of the loans in the pool have lock-out provisions and exculpstory clauses. There are eight loans in the pool, each with a par value of 55M. The loans are nonamortizing (interest-only), esch paying a coupon rate of 10%, and all will retire within the next threo years. Four of the loans will retire in year two, the remainiag four in year three. (a) Write out the caht flows from interest and principal repayment generated by tho underlying loans for each of the three years assuming there is no default in the pool. (b) The CMBS you isnue consiats of a veciot tranche, A, s subordiate tranche. B, and an 10 tranche, X. The par value of the A tranche is 825M, the par for the B tranche is 810M, and the X trancbe teotives any coupon. payments is excess of what is paid to A snd B. The A trande pays a coupos of 8%, the B tranche a coupon of 10%. What are the each flows reotived by the A, B and X tranches in esch of the thres yearn sasureing po defaule