You are working as a Solutions Architect in a university where you take part in a migration to the cloud. Their HPC Clusters are meant to leverage research processes relying on MPI applications in Biology and Physics departments. There are some decisions to make to manage the cluster correctly. What option is the most appropriate to set up the environment?

Answer options:

A.AWS ParallelCluster is a fully managed cluster. EFA support is enabled by default but can be disabled dynamically, on-demand on any EC2 instance.
B.To use EFA, the primary ENI has to be detached, EFA enabled, and reattach the ENI either at the launch of the instance or added to a stopped instance. This will get OS-bypass capabilities for low-latency network communications with other instances on the same subnet.
C.You are responsible for operating ParallelCluster, including required maintenance on EC2 instances and batch schedulers, security patching, user management, and MPI troubleshooting. EFA support is enabled by default but can be disabled dynamically, on-demand on any EC2 instance.
D.To use EFA, it has to be enabled with AWS ParallelCluster to get OS-bypass capabilities for low-latency network communications with other instances on the same subnet. This support can be enabled in specific instance types either at the launch of the instance or added to a stopped instance.

Answer: D
This option guarantees one of the fastest and scalable settings in HPC Clusters. AWS ParallelCluster supports EFA, which can get OS-bypass capabilities (kernel-bypass networking), which is possible only in specific instance types and limited to a single subnet. Also, you cannot attach an EFA to an instance that is in the running state.
Option A is incorrect because AWS ParallelCluster is a self-service solution.
Option B is incorrect because you cannot detach the primary ENI.
Option C is incorrect because EFA support is not enabled by default and is not supported in any EC2 instance type.
References:
https://go.aws/2ys7erk
https://amzn.to/3exVVic