What should a solutions architect recommend?
Use an Auto Scaling group with a cluster placement group.
Use an Auto Scaling group with single Availability Zone in the same AWS Region.
Use an Auto Scaling group with multiple Availability Zones in the same AWS Region.
Use a Network Load Balancer with multiple Amazon EC2 Dedicated Hosts as the targets.
Explanations:
A cluster placement group ensures that instances are placed close together on the underlying hardware to minimize network latency, which is ideal for applications requiring low-latency communication.
Using a single Availability Zone may limit fault tolerance and scalability. While it could reduce latency, it’s not the best for multi-instance applications that need high availability or fault tolerance.
While multiple Availability Zones offer high availability, the latency between zones can be higher than within a single zone, making this option less ideal for minimal latency between instances.
A Network Load Balancer and EC2 Dedicated Hosts focus on specific network performance and dedicated hardware, but they don’t necessarily reduce latency between instances in the way a placement group can.
I estimate that the answer is:
Use an Auto Scaling group with a cluster placement group.