Which method may a federal agency use to obtain information?

A federal agency has several means at its disposal to obtain information, and one of the primary methods includes utilizing a summons, a subpoena, or a warrant. Each of these mechanisms serves a distinct purpose and can be employed based on the specific needs of the agency's investigation or regulatory activities.

A summons typically allows an agency to compel the attendance of a person or the production of documents in a non-adversarial manner, often used for routine inquiries or information gathering. A subpoena, on the other hand, is a more formal request for documents or testimony, which has the force of law and can be enforced in court if not complied with. Finally, a warrant provides the agency with judicial authority to search a location or seize evidence, typically in circumstances where there is probable cause that a violation of law has occurred.

These tools are essential for federal agencies to effectively carry out their mandates, ensuring they can gather necessary information while complying with legal standards. This capability allows agencies to conduct thorough investigations, enforce regulations, and take necessary actions to uphold the integrity of their operations.

The other options presented are too restrictive, as they limit the methods by which an agency can obtain information, overlooking the breadth of legal tools available to federal agencies in the administrative framework.