You have just set up a classic load balancer with EC2 Instances distributed over 2 subnets. The first subnet has one instance and the other subnet has 3 instances. You have noticed that the load is high on the single instance located in the first subnet. Which of the following settings can be set on the load balancer to ensure even distribution of traffic across all of the instances

Answer options:

A.Configure connection draining
B.Configure sticky sessions
C.Configure Proxy protocol
D.Configure Cross-Zone Load balancing

Answer - D
The AWS documentation mentions the following
If the load balancer nodes for your Classic Load Balancer can distribute requests regardless of Availability Zone, this is known as cross-zone load balancing. With cross-zone load balancing enabled, your load balancer nodes distribute incoming requests evenly across the Availability Zones enabled for your load balancer
For more information on cross zone load balancing, please visit the below link:
http://docs.aws.amazon.com/elasticloadbalancing/latest/classic/enable-disable-crosszone-lb.html