An upgrade of IaaS components fails for two servers running Website and Manager services on each server. The administrator started the upgrade on both servers at the same time.
What is a likely cause of the failure?
A. Each individual server upgrade must be allowed to complete before starting another server upgrade.
B. The Parallel Upgrade option in the upgrade wizard was not selected before starting the upgrade
C. The Upgrade Order option in the upgrade wizard was not specified before starting the upgrade
D. Wait for the first server upgrade to start processing before starting another server upgrade.
