An application is being set up by launching EC2 Instances and an Elastic Load balancer. It needs to be ensured that the application is made highly available and also a uniform distribution of traffic across the various backend nodes. How can you accomplish this? Choose 2 answers from the options given below.

Answer options:

A.Ensure that the Instances are launched across multiple regions.
B.Ensure that the Instances are launched across multiple availability zones.
C.Ensure that cross zone load balancing is enabled on the load balancer.
D.Ensure that the load balancer is created across multiple regions.

Correct Answers: B and C
For maximum availability, ensure that the Instances are placed across multiple availability zones.
The AWS Documentation mentions the following.
When you enable an Availability Zone for the load balancer, Elastic Load Balancing creates a load balancer node in the Availability Zone. By default, each load balancer node distributes traffic across the registered targets in its Availability Zone only. If you enable cross-zone load balancing, each load balancer node distributes traffic across the registered targets in all enabled Availability Zones. 
Options A and D are incorrect since the resources need to be created in the same region.
For more information on the Network Load Balancer, please visit the below URLs-
https://docs.aws.amazon.com/elasticloadbalancing/latest/network/introduction.html
https://docs.aws.amazon.com/elasticloadbalancing/latest/classic/enable-disable-crosszone-lb.html
https://aws.amazon.com/about-aws/whats-new/2018/02/network-load-balancer-now-supports-cross-zone-load-balancing
https://docs.aws.amazon.com/elasticloadbalancing/latest/userguide/how-elastic-load-balancing-works.html