Final answer:
A Catholic church official refusing to rent to a Buddhist solely based on religion constitutes illegal religious discrimination under U.S. federal civil rights laws.
Step-by-step explanation:
The situation described involves a Catholic church official who refuses to rent to a Buddhist, specifically stating that the accommodations are only for members of the congregation. This practice falls within the realm of religious discrimination, which treats a person unfavorably due to their religious beliefs. In the United States, such discrimination is illegal under federal civil rights laws, which protect people of all religions, as well as those with sincerely held ethical, moral, or religious beliefs. The refusal to rent solely based on religious affiliation would be considered illegal barring any specific exemptions that might apply to religious organizations under certain circumstances. However, generally, the law prohibits discrimination in housing based on religion. Therefore, based on the provided information, the official's refusal to rent would be considered illegal.