Final answer:
The Federal Home Loan Bank Board is not involved in the secondary mortgage market, unlike Fannie Mae, Ginnie Mae, and Freddie Mac, which are. Option a is the answer.
Step-by-step explanation:
The organization that is not involved in acquiring mortgages on the secondary market is a) Federal Home Loan Bank Board. The other entities listed, namely b) Fannie Mae, c) Ginnie Mae, and d) Freddie Mac, are all actively involved in the purchase and securitization of mortgages on the secondary market. These institutions play significant roles in providing liquidity to the mortgage market, which in return, impacts the availability and affordability of home loans.