Final answer:
In water polo, the center forward or hole set is the only offensive player permitted inside the "two meter line" without the ball, while defensive players may only be inside this area to closely guard an offensive player.
Step-by-step explanation:
In water polo, the only player permitted inside the "two meter line" without the ball is the offensive player, commonly referred to as the center forward or hole set. This rule appropriately positions players around the goal and dictates spacing within the playing field. Defensive players, on the other hand, may be within the two-meter area only if they are closely guarding an offensive player. Still, there must be no offensive player between them and the goal except when the offensive player has the ball. Essentially, this area operates as a space to create scoring opportunities and strategic play.