Which steps should the SysOps Administrator take to prevent this from happening in this future?

A company’s website went down for several hours. The root cause was a full disk on one of the company’s Amazon EC2 instances.

Which steps should the SysOps Administrator take to prevent this from happening in this future?
A . Configure Amazon CloudWatch Events to filter and forward AWS Health events for disk space utilization to an Amazon SNS topic to notify the Administrator.
B . Create an AWS Lambda function to describe the volume status for each EC2 instance.
Post a notification to an Amazon SNS topic when a volume status is impaired.
C . Enable detailed monitoring for the EC2 instances. Create an Amazon CloudWatch alarm to notify the
Administrator when disk space is running low.
D . Use the Amazon CloudWatch agent on the EC2 instances to collect disk metrics. Create a CloudWatch alarm to notify the Administrator when disk space is running low.

Answer: D