Which office is involved with matters related to immigration litigation?

The Office of Immigration Litigation is specifically tasked with handling litigation related to immigration matters. This office operates within the Department of Justice and represents the government in legal proceedings involving immigration issues, such as appeals in immigration court cases and defending the decisions made by immigration agencies. Its primary focus is to ensure that immigration laws are appropriately enforced within the judicial system.

The other offices listed, such as the Office of Inspector General, primarily deal with oversight and investigation of agency actions, while the Office of Information Technology focuses on managing IT resources. The Office of Legislative Affairs is responsible for communication and coordination with Congress regarding legislative matters, rather than directly addressing immigration litigation. Therefore, the Office of Immigration Litigation's specific focus on legal issues surrounding immigration makes it the correct answer.