What action is essential for the monitors to perform during the AL event?

Setting up the event and instructing Marines is crucial because it ensures that the participants are well-informed about the expectations and requirements of the AL (Ammunition Lift) event. Proper setup includes arranging the necessary equipment and ensuring safety measures are in place. Furthermore, clear instructions help participants understand the objectives of the test and how to execute their performance accurately. This foundational step promotes a smooth operation during the event and allows for a consistent approach to evaluating each participant's performance. Without effective setup and guidance, the integrity of the test could be compromised, making it difficult to assess each Marine fairly and accurately.