Which of the following is a best practice when configuring maintenance windows?

A. Disable any glass tables that reference a KPI that is part of an open maintenance window.

B. Develop a strategy for configuring a service’s notable event generation when the service’s maintenance window is open.

C. Give the maintenance window a buffer, for example, 15 minutes before and after actual maintenance work.

D. Change the color of services and entities that are part of an open maintenance window in the service analyzer.

Explanation:
It’s a best practice to schedule maintenance windows with a 15- to 30-minute time buffer before and after you start and stop your maintenance work. 

Reference: https://docs.splunk.com/Documentation/ITSI/4.10.2/Configure/AboutMW