When can you legally turn right at a red light?

Turning right at a red light is generally permitted under specific conditions, which aligns with the correct answer. In most jurisdictions, a driver may legally turn right at a red light after coming to a complete stop, ensuring that the intersection is clear of incoming traffic and any pedestrians are safely out of the way. This rule promotes traffic flow while ensuring safety, as drivers must yield to all other road users before making the turn.

The other choices do not accurately reflect the legal guidelines. For instance, stating that a right turn is only allowed when a sign prohibits it is misleading since the default assumption is that a right turn is allowed unless specifically prohibited by signage. Saying it is illegal at all times is incorrect because many places permit the turn after the necessary precautions. Lastly, while a green arrow indicates a driver can proceed, it specifically applies to directions indicated by the arrow rather than to the broader context of turning at a red light.