What commonly results in a chop block penalty?

The correct answer highlights a specific scenario where a chop block penalty is most commonly enforced. A chop block occurs when one player blocks an opponent low while that opponent is already engaged with another player who is blocking high. This dual approach to blocking creates an unsafe situation for the player being blocked, as it targets both high and low, leading to potential injuries.

In this case, option B describes a situation where a player is blocking below the waist while already engaged with another blocker. This action can contribute to the violation of the chop block rule because it indicates that the player is attempting to unreasonably place the engaged opponent in a vulnerable position. Thus, the rules are in place to protect players from these types of dangerous blocks.

Understanding this context helps clarify why the option is aligned with the specifics of chop block penalties according to NFHS regulations, emphasizing player safety on the field.