Final answer:
The Fair Housing Act does not expressly prohibit discrimination on the basis of marital status; it outlaws blockbusting, discriminatory advertising, and redlining.
Step-by-step explanation:
The federal Fair Housing Act prohibits many forms of discrimination in housing; however, it does not ban all discriminatory practices. The Act makes it illegal to discriminate on the basis of race, color, national origin, religion, sex, familial status, or disability. Given the choices provided in the question, the federal Fair Housing Act prohibits blockbusting,discriminatory advertising, and redlining. However, the Act does not specifically prohibit discrimination on the basis of marital status. Therefore, among the options listed, discriminating on the basis of marital status is the one that the Fair Housing Act does not expressly prohibit.