Which of the following is NOT a protected class under the Fair Housing Act?

Under the Fair Housing Act, the protected classes are specifically defined to prevent discrimination in housing based on certain characteristics. These include race, color, national origin, religion, sex (gender), familial status, and disability. Age is not included in this list, thus making it the correct answer to the question.

Race is protected because it aims to eliminate housing discrimination based on ethnicity or racial background. Gender is also a protected class, ensuring that individuals cannot be discriminated against based on their sex. Disability is included to protect individuals with physical or mental disabilities from being discriminated against in housing situations. Age, however, does not fall under the protections provided by the Fair Housing Act, which is why it is identified as the option that does not represent a protected class.