What is the purpose of a subpoena in legal proceedings?

The purpose of a subpoena in legal proceedings is primarily to require someone to answer questions or provide information. This legal document is issued by a court or legal authority and mandates that an individual either appear in court to testify or produce specified documents and evidence relevant to a case. Subpoenas are essential tools in the discovery phase of legal proceedings, as they help ensure that all pertinent information is available for consideration by the parties involved and the court.

In contrast, the other options represent different legal instruments or decisions that do not align with the purpose of a subpoena. Community service relates to sentencing following a conviction, search and seizure involve warrants that authorize law enforcement to collect evidence, and granting immunity pertains to legal protections that prevent prosecution in exchange for cooperation, typically in criminal cases. Thus, the correct option accurately captures the role of a subpoena in facilitating the legal process.