Pvt Thompson is directed to move a 24-foot metal extension ladder from the supply room to the barracks for a work detail the next day. She has to cross a 300-meter open field to get to the barracks. There is a thunderstorm in the local area forecasted to last for two hours. Pvt Thompson decides to wait until the thunderstorm passes before moving the ladder across the field. Which type of control option did this Marine use to mitigate the risk of the thunderstorm