What is the purpose of a "subpoena"?

A subpoena is a legal document that commands an individual to appear in court as a witness or to produce certain documents, records, or evidence relevant to a legal proceeding. The primary function of a subpoena is to ensure that the legal process operates smoothly and allows parties to present relevant information that may be critical to the case at hand.

In this context, option B is correctly identified as the purpose of a subpoena. When someone receives a subpoena, they are legally obliged to comply, which facilitates the gathering of necessary testimony or evidence that contributes to the judicial process. This ensures that justice is served and that all pertinent information is considered during a trial or hearing.

The other options present different legal concepts that do not align with the definition and purpose of a subpoena. For instance, authorizing a search of a property relates to a search warrant, which is a separate procedure involving law enforcement. Preventing contact between individuals typically pertains to restraining orders or injunctions, which are designed to protect individuals from harassment or harm. Granting custody of a child falls under family law and legal custody arrangements, which are also unrelated to the function of a subpoena.