Which government agency is responsible for investigating serious violations of the Privacy Rule?

The correct choice identifies the Office of Civil Rights as the agency responsible for enforcing and investigating serious violations of the Privacy Rule under HIPAA. This office operates within the Department of Health and Human Services and is specifically tasked with ensuring compliance with HIPAA's privacy and security standards.

When serious violations are suspected, the Office of Civil Rights has the authority to investigate complaints, conduct compliance reviews, and enforce penalties if necessary. This role is crucial as it directly relates to the protection of individual health information and privacy rights, aligning with the primary goals of HIPAA.

In contrast, while the Department of Justice does play a role in criminal prosecutions related to healthcare fraud, it is not primarily responsible for investigating issues specifically within the jurisdiction of the Privacy Rule. The Department of Health and Human Services oversees the enforcement but delegates this specific function to the Office of Civil Rights. The Federal Trade Commission has a different focus, primarily on consumer protection and anti-competitive practices, rather than on health information privacy enforcement under HIPAA.