You have multiple Amazon EC2 instances running in various clusters within the same region. How will you ensure that the EC2 instances will communicate between the clusters without any bandwidth restrictions and also perform with the highest network performance, low latency, and low jitter?

Answer options:

A.Cluster placement group
B.Enhanced networking
C.Amazon PV AMI
D.Amazon HVM AMI
E.Amazon Linux
F.Amazon VPC Endpoints

Answer - A, B, and D
Option A is CORRECT because Cluster placement groups are recommended for applications that benefit from low network latency, high network throughput, or both. The majority of the network traffic is between the instances in the group.
Option B is CORRECT because Enhanced networking uses single root I/O virtualization (SR-IOV) to provide high-performance networking capabilities on supported instance types.
Option C is incorrect because it is recommended to use HVM AMIs for better performance than PV AMIs.
D. Option D is CORRECT because HVM AMIs are presented with a fully virtualized set of hardware and boot by executing the master boot record of the root block device of your image. This virtualization type provides the ability to run an operating system directly on top of a virtual machine without any modification as if it were run on the bare-metal hardware. The Amazon EC2 host system emulates some or all of the underlying hardware presented to the guest. HVM guests can take advantage of hardware extensions that provide fast access to the underlying hardware on the host system.
Option E is incorrect because using Amazon Linux does not necessarily improve any performance.
Option F is incorrect because if we enable a VPC Endpoint connection from a VPC EC2 instance to other AWS services, then the users experience slowness.
For more information on Enhanced Networking, please visit the URL 
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/enhanced-networking.html
Linux Amazon Machine Images use one of two types of virtualization: paravirtual (PV) or hardware virtual machine (HVM). The main difference between PV and HVM AMIs is the way in which they boot and whether they can take advantage of special hardware extensions (CPU, network, and storage) for better performance. We recommend that you use current generation instance types and HVM AMIs when you launch your instances for the best performance. 
For more information on Enhanced Networking, please visit the URL-
http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/virtualization_types.html