Who represents a defendant if private counsel is unavailable?

The choice indicating the Office of the Public Defender is correct because this office is specifically designated to represent defendants who cannot afford private legal counsel in criminal cases. The public defenders are licensed attorneys who specialize in defending clients who require legal assistance but lack the means to hire a private lawyer.

In situations where a defendant does not have private counsel, the court typically appoints a public defender to ensure that the defendant's rights are upheld and that they receive a fair trial. This system is crucial in maintaining the ethical and constitutional guarantee of legal representation for all individuals, regardless of their financial situation.

The other options involve entities that do not provide defense representation for a defendant. A retained law firm implies that a defendant has the resources to hire private legal representation, which contradicts the premise of the question. The Public Prosecution Office represents the state in criminal matters, focusing on prosecuting defendants rather than defending them. Lastly, the State Attorney General typically handles legal matters for the state and is not responsible for defending individual defendants in criminal cases. Thus, the Office of the Public Defender is the appropriate and designated option for providing legal representation to those in need.