Which combination of steps will accomplish this?
(Choose two.)
Create an Amazon CloudWatch dashboard to monitor the memory usage metrics on the instance over time.
Create an alarm on the dashboard that publishes an Amazon SNS notification to alert the CIO when a threshold is passed.
Create an alarm on the metric that publishes an Amazon SNS notification to alert the CIO when a threshold is passed.
Create an alarm on the AWS Personal Health Dashboard that publishes an Amazon SNS notification to alert the CIO when the system is out of memory.
Configure the Amazon CloudWatch agent to collect and push memory usage metrics on the instance.
Explanations:
Amazon CloudWatch does not natively provide memory usage metrics for EC2 instances, so creating a dashboard for memory usage will not work without additional configuration.
A CloudWatch dashboard is for visualizing metrics, not for setting alarms. You need to set alarms directly on metrics, not through a dashboard.
Creating an alarm on the memory metric is the correct approach to alert when memory usage exceeds a threshold. This can publish an SNS notification for alerting.
The AWS Personal Health Dashboard provides information about AWS service health, not individual EC2 instance memory usage. It cannot be used for this purpose.
The CloudWatch agent is required to collect memory usage metrics on an EC2 instance because CloudWatch does not collect memory metrics by default for EC2 instances.
From my point of view, the answer is:
Create an alarm on the metric that publishes an Amazon SNS notification to alert the CIO when a threshold is passed.