Final answer:
A broker can legally not show a house to anyone when the owner is out of town and has instructed not to show the home (option C). Discrimination based on race, such as not showing a home to a minority in a white neighborhood, is illegal under the 1866 Civil Rights Act.
Step-by-step explanation:
Under the 1866 Civil Rights Act, there are no circumstances under which a broker may legally refuse to show a home in a white neighborhood to a minority due to their race.
The law prohibits racial discrimination in all property transactions. However, there is one situation where a broker might legally not show a home, which is unrelated to the potential buyer's minority status.
That situation is provided in option C, where the owner is out of town and has specifically instructed the broker not to show the home to anyone during their absence.
This instruction would apply to all potential buyers, regardless of race. Options A (never), B (when the minority has given up their rights under the 1866 Civil Rights Act), and D (when the agent sincerely believes violence would ensue) are not legally valid reasons to refuse showing a home to a minority.
Discriminatory housing practices such as refusing to sell houses to ethnic minorities in white neighborhoods are illegal and have a long history of contributing to segregation and inequality. Option C