A security engineer on a large enterprise network needs to schedule maintenance within a fixed window of time. A total outage period of four hours is permitted for servers. Workstations can undergo maintenance from 8:00 pm to 6:00 am daily. Which of the following can specify parameters for the maintenance work? (Select TWO).
A . Managed security service
B . Memorandum of understanding
C . Quality of service
D . Network service provider
E . Operating level agreement
Answer: B, E