Which domain name suffix indicates ownership by the United States government?

The domain name suffix that indicates ownership by the United States government is ".gov." This designation is specifically reserved for governmental entities at the federal, state, local, and tribal levels within the United States. The use of ".gov" helps to assure users that the website represents an official government body, which is essential for establishing trust and authenticity in government-related information.

On the other hand, the suffix ".org" is typically used by non-profit organizations and does not signify any governmental affiliation. ".edu" is reserved for accredited educational institutions, while ".com" is primarily used for commercial entities and businesses. Therefore, ".gov" uniquely identifies government websites, making it the correct answer.