What is the ruling if B1 takes a swing and contacts the pitch while having one foot entirely outside the batter's box?

When a batter takes a swing and contacts the pitch while having one foot entirely outside the batter's box, the action is ruled as a violation of the rules governing the batter's position. According to the regulations, a batter must have both feet entirely within the batter's box when they make a swing at the ball. If the batter fails to adhere to this requirement, the pitch is nullified, and the batter is considered out. This ensures that the integrity of the batting position is maintained, allowing for fair play and preventing any unintended advantage that might result from contacting the ball while not in the appropriate position.

In this scenario, the other choices would not apply as the swing with one foot outside the box compromises the legality of the hit and does not count as valid, nor does it allow the batter to proceed to a base or be considered safe.