A tightly-coupled high-performance computing (HPC) job needs the lowest possible network latency and highest throughput between a group of EC2 instances. Which placement strategy should be used?
A) A cluster placement group.
B) A spread placement group.
C) Spreading instances across multiple regions.
D) Distributing instances across many AZs.
Correct Answer: A
Explanation: A cluster placement group packs instances close together within a single AZ on high-bandwidth, low-latency interconnects — ideal for tightly-coupled HPC. (B) spread placement maximizes isolation, increasing latency. (C) and (D) separate instances, raising latency — the opposite of the goal.