Final answer:
Ginnie Mae insures mortgage-backed securities in the secondary mortgage market, by guaranteeing the timely payment of principal and interest to investors.
Step-by-step explanation:
The question is about what Ginnie Mae does in the secondary mortgage market. Among the provided options, the best description of Ginnie Mae's role is that it insures mortgage-backed securities. Ginnie Mae, or the Government National Mortgage Association, is a government-owned corporation within the U.S
Department of Housing and Urban Development (HUD). Ginnie Mae does not buy or sell mortgage-backed securities, regulate the mortgage industry, or provide loans to homebuyers. Instead, it guarantees investors the timely payment of principal and interest on mortgage-backed securities backed by federally insured or guaranteed loans -- mainly loans insured by the Federal Housing Administration (FHA) or guaranteed by the Veterans Administration (VA).