An organization has setup Auto Scaling with ELB. Due to some manual error, one of the instances got
rebooted. Thus, it failed the Auto Scaling health check. Auto Scaling has marked it for replacement. How can
the system admin ensure that the instance does not get terminated?

A.
Update the Auto Scaling group to ignore the instance reboot event

B.
It is not possible to change the status once it is marked for replacement

C.
Manually add that instance to the Auto Scaling group after reboot to avoid replacement

D.
Change the health of the instance to healthy using the Auto Scaling commands

Explanation:
After an instance has been marked unhealthy by Auto Scaling, as a result of an Amazon EC2 or ELB health
check, it is almost immediately scheduled for replacement as it will never automatically recover its health. If the
user knows that the instance is healthy then he can manually call the SetInstanceHealth action (or the assetinstance- health command from CLI. to set the instance’s health status back to healthy. Auto Scaling will
throw an error if the instance is already terminating or else it will mark it healthy.