Wells Fargo issues a CMBS. The mortgage poolconsists of interest only loans, with a totalloan amount of $15 million. Assume the mortgage rate in the pool is 11%, the mortgages areannually compounded, and the loan maturity is 4 years. There are three tranches in the CMBS: 1.Tranche A, with anamount of$10 millionat 8% coupon rate, 2. Tranche B, $3 million at 10% coupon rate, 3. the residual tranche, with $2 million. Thematurity of the MBS is4 years. Suppose some loans are in default, so only 70% of the original loan amount can be recovered at the end of 4th year. However, the mortgage pool can still generate the same amount of cash flow available in year 4 as those in the first 3 years . What is the investor return for Tranche B for the 4 year period?