When mortgages are sold after they have been funded, they are considered part of the:

The primary mortgage market refers to the initial stage where loans are originated and funded directly between borrowers and lenders. Mortgages in this market are new loans, and once they are funded, they are no longer part of the primary market, making this choice incorrect.

The Rural Housing Service is a government agency that provides loans and grants to promote homeownership in rural areas. While it plays a role in facilitating mortgage financing for certain demographics, it does not pertain to the buying and selling of mortgages once they have been funded, thus making this choice irrelevant in the context of the question.

The Federal Reserve System is the central banking system of the United States, responsible for monetary policy and regulating financial institutions. While it influences interest rates and overall economic conditions, it does not engage in the buying or selling of individual mortgages, making this choice incorrect.