Amazon RDS provides Amazon CloudWatch metrics for your DB Instance deployments at no ad-ditional charge. You can use the AWS Management Console to view key operational metrics for your DB Instance deployments, including ____.

A. I/O activity, DB Instance connections, and number of users
B. DB Engine Version Management
C. username, I/O activity, and DB Instance connections
D. compute/memory/storage capacity utilization, I/O activity, and DB Instance connections