What must a referee ensure before signaling the end of a period?

The correct answer highlights the referee's responsibility to ensure that all player penalties have been properly addressed before signaling the end of a period. The rationale behind this is that an unassessed penalty could affect the outcome or integrity of the game. If there are any fouls committed during the play, the referee must account for them, as they may involve penalties that dictate the next actions, such as replaying the down or implementing yardage adjustments.

Ensuring all penalties are addressed is crucial to maintaining fair play, as penalties can change the dynamics of the game and impact the strategies of both teams. Therefore, it is essential that the referee confirms that no outstanding penalties remain before concluding the period, which facilitates the smooth continuation of the game without unresolved issues.

Other considerations like the accuracy of the game clock, scoring plays, or timeouts are important but secondary to the necessity of addressing any penalties that may have occurred.