Which of the following is NOT a protected classification under the FHA?

The correct choice is identified as income level, which is not a protected classification under the Fair Housing Act (FHA). The FHA aims to eliminate discrimination in housing based on certain specified categories. These protected classes include race, color, national origin, religion, sex (gender), familial status, and disability.

Income level, while certainly a factor in housing affordability and access, does not fall within the categories that the FHA specifically aims to protect against discrimination. This means that while housing providers cannot discriminate based on income in the context of other protected classes, such as refusing to rent to someone solely because of their lower income does not relate to the Fair Housing Act's provisions, which focus on equal access regardless of race, gender, or familial status.

The other classifications listed—race, gender, and familial status—are explicitly protected under the FHA, prohibiting discrimination and ensuring that no individual is denied housing opportunities based on these characteristics.