Taj Needs to Install a Set of Updates for an Application

Multiple Choice

Taj needs to install a set of updates for an application server that will restart the server three times. Which of the following should prevent at least some of the users from calling in to report an outage? (Choose two)

A) Disable the service desk phone number temporarily.
B) Schedule a maintenance window.
C) Perform the update when the fewest number of people are using the application.
D) Make a backup of the application server.