Final answer:
The correct answer is Title VII of the Civil Rights Act, which is the major legislation that prohibits employment discrimination based on race, color, religion, sex, or national origin.
Step-by-step explanation:
The major legislation outlawing employment discrimination and specifically prohibiting discrimination on the basis of race, color, religion, sex, or national origin is Title VII of the Civil Rights Act.
Title VII of the Act constitutes a crucial part of employment law that ensures equal employment opportunities and protects against discrimination in various aspects of employment including hiring, benefits, promotions, and termination. Not only does it cover these five protected categories, but subsequent amendments and acts like the Pregnancy Discrimination Act of 1978 have expanded its protections to include pregnancy status, assuring that women are not discriminated against due to pregnancy, childbirth, or related medical conditions.