Final answer:
The action that does not violate the California Fair Housing Law is 'The owner of a single-family residence refuses to sell to a couple because they are unmarried,' since this does not involve discrimination against a protected class under federal and state fair housing laws.
Step-by-step explanation:
Out of the options provided, the action that would NOT violate the California Fair Housing Law is:
A) The owner of a single-family residence refuses to sell to a couple because they are unmarried.
This action does not involve discrimination based on race, color, religion, sex, disability, familial status, or national origin, which are protected under both the California Fair Housing Law, also known as the Unruh Civil Rights Act, and the Federal Fair Housing Act of 1968.
It is important to note that while the Federal Fair Housing Act does not explicitly mention protection for unmarried couples, the prohibition against discrimination based on familial status may offer some degree of protection. However, marital status is protected under California state law, but there are exceptions for certain types of privately-owned, single-family residences.