A gaming application is deployed on four Amazon EC2 instances in a default VPC.The SysOps Administrator has noticed consistently high latency in responses as data is transferred among the four instances.There is no way for the Administrator to alter the application code.The MOST effective way to reduce latency is to relaunch the EC2 instances in:
a dedicated VPC.
a single subnet inside the VPC.
a placement group.
a single Availability Zone.
Explanations:
A dedicated VPC does not improve latency within EC2 instances. It separates instances for isolation.
Placing instances in a single subnet does not guarantee low latency; instances could be in different AZs.
A placement group helps reduce latency by placing instances physically close to each other within the same AZ.
Although using a single AZ may reduce latency, it doesn’t directly address the physical placement of instances like a placement group does.
I think the answer is:
a placement group.