A SysOps administrator is using AWS Compute Optimizer to get recommendations for a fleet of Amazon EC2 instances. After the analysis is complete, some of the EC2 instances are missing from the Compute Optimizer dashboard.
What is the cause of this issue?

A. The missing instances do not have the Amazon CloudWatch agent installed.
B. Compute Optimizer does not support the instance types of the missing instances.
C. Compute Optimizer already considers the missing instances to be optimized.
D. The missing instances are running a Windows operating system.