The practice of denying a mortgage loan to a borrower based on the area's racial or ethnic composition is best known as:

Profiling generally refers to the practice of targeting individuals based on characteristics such as race or ethnicity, but it does not specifically pertain to the denial of mortgage loans. While profiling can be a component of discriminatory practices, it lacks the specific context of geographical and financial discrimination that defines redlining.

Blockbusting involves inducing homeowners to sell their properties at lower prices by instilling fear of racial integration in their neighborhoods. Although it relates to racial discrimination in housing, it focuses more on manipulating market conditions rather than the outright denial of mortgage loans based on area demographics.

Straw buying refers to a fraudulent scheme where one person purchases a property on behalf of another who may not qualify for the mortgage. This practice is unrelated to racial or ethnic discrimination in lending and does not involve denying loans based on area demographics.