At the moment of serve, which players shall be in correct serving?

At the moment of serve, it is required that all players, including the libero, must be in their correct positions on the court. This means that all players should have checked in with the official and be in legal positions before the serve is made. The libero, a specialized defensive player, is allowed to participate in the serving instance and must be positioned correctly on the court like any other player.

Having both front-row and back-row players in proper locations allows for fair play and adherence to the rules set forth by volleyball governing bodies. This ensures the integrity of the game and enables teams to correctly execute their strategies during the serve.

In contrast, the other options suggest limitations on players' positions, which do not align with the rules governing player positioning at the serve. This provides a clearer understanding of the requirements for proper serving in a volleyball match.