What should happen if B-6 and B-7 report to enter after the warning horn sounds for A-1's substitution?

The correct answer is that B-6 and B-7 cannot enter the game since they reported after the warning. In basketball, there are specific rules in place regarding substitutions, especially in relation to the timing of when players report to enter the game. The warning horn serves as a signal indicating that the deadline for substitutions has passed. Once that warning horn sounds, any player who wishes to enter the game must do so before that point.

When B-6 and B-7 report after the warning, they are effectively outside the allowed timeframe for substitution. This rule is designed to ensure smooth gameplay and to prevent disruptions during critical moments of the game. Allowing substitutions after the warning would lead to potential confusion and disrupt the flow of play.

Therefore, since B-6 and B-7 did not adhere to the substitution reporting timeline and came after the warning, they are not eligible to enter the game at that moment.