An ELB is diverting traffic across 5 instances. One of the instances was unhealthy only for 20 minutes. What will happen
after 20 minutes when the instance becomes healthy?

A.
ELB will never divert traffic back to the same instance

B.
ELB will not automatically send traffic to the same instance. However, the user can configure to start sending traffic to the same instance

C.
ELB starts sending traffic to the instance once it is healthy

D.
ELB terminates the instance once it is unhealthy. Thus, the instance cannot be healthy after 10 minutes

Explanation:
AWS Elastic Load Balancing continuously checks the health of an instance. If one of the instances is unhealthy it stops
sending traffic to it and automatically reroutes the traffic to the remaining running EC2 instances. If the failed EC2 instance
is restored, Elastic Load Balancing will again start sending traffic to that instance.
http://docs.aws.amazon.com/ElasticLoadBalancing/latest/DeveloperGuide/SvcIntro.html