What should an official enforce if a player has blood on their jersey?

When a player has blood on their jersey, the proper enforcement by an official is that the player must leave the game until the situation is resolved. This protocol is in place to ensure the safety of all players on the court and to maintain the integrity of the game. Blood is considered a potential health hazard, and it's crucial to address it promptly.

The player must leave the game to receive appropriate medical attention if necessary, and to have their jersey cleaned or changed if it has become stained with blood. This action is not only about the player's well-being but also protects opponents and teammates from potential exposure to bloodborne pathogens.

The other choices do not adequately address the need for player and game safety. Allowing the player to stay if the bleeding is stopped can be risky if the blood remains on the uniform, and continuing to play with a band-aid may not sufficiently contain any potential further bleeding or health hazards. Simply changing the jersey without addressing the underlying issue does not fulfill the requirement of player safety and proper protocol.