What does Freddie Mac primarily do?

Freddie Mac primarily focuses on purchasing conventional mortgage loans from lenders. This action helps provide liquidity, stability, and affordability to the mortgage market. By buying these loans, Freddie Mac allows lenders to free up capital, enabling them to offer more loans; this, in turn, helps potential homebuyers access financing more easily. This function is crucial to increasing the availability of mortgage credit and supporting homeownership in the United States.

The other options do not accurately represent Freddie Mac's role. For instance, it does not handle tax filings, offer direct loans to consumers, or regulate interest rates on mortgages or loans. Instead, its primary mission revolves around secondary mortgage market activities—making option B the correct choice.