Which of the below parameters should the user consider …

A user is setting up an Elastic Load Balancer(ELB). Which of the below parameters should the user consider so as the
instance gets registered with the ELB?

A.
ELB DNS

B.
IP address

C.
Security group

D.
ELB IP

Explanation:
The EC2 instances are registered with the load balancer using the IP addresses associated with the instances. When an
instance is stopped and then started, the IP address associated with the instance changes. This prevents the load
balancer from routing traffic to the restarted instance. When the user stops and then starts registered EC2 instances, it
is recommended that to de-register the stopped instance from load balancer, and then register the restarted instance.
Failure to do so may prevent the load balancer from performing health checks and routing the traffic to the restarted
instance.
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/TerminologyandKeyConcepts.html