Leopold, a manager, instructed his subordinate, Allison, to remind her staff that any request for overtime-pay work this weekend could only be authorized by the division manager. Allison misunderstood Leopold and explained to her staff that all were required to work this weekend with overtime pay that had been authorized by the division manager. In this context, why would it have been better for Leopold to communicate to Allison through an e-mail instead of instructing her orally.