What is the appropriate action if a batter steps out of the batter's box repeatedly between pitches?

If a batter steps out of the batter's box repeatedly between pitches, the appropriate action is to give a warning for delay of game. This practice is intended to maintain the flow of the game and ensure that play continues in a timely manner. When a batter steps out consistently, it can disrupt the rhythm of the game and lead to unnecessary delays.

By issuing a warning, the umpire signals that the behavior is not acceptable and emphasizes the importance of staying in the box and being prepared to hit. This establishes a standard for the conduct expected from the batter moving forward. If the behavior continues after the warning, the umpire may impose further penalties, which could escalate depending on the situation.

The other options either do not adequately address the issue or would not enforce the necessary discipline to promote sportsmanship and a smooth game pace.