Private-subnet instances transfer large volumes of data to S3 through a NAT Gateway, incurring significant NAT data-processing charges. How can the architect reduce these costs?
A) Add a second NAT Gateway.
B) Create a Gateway VPC endpoint for S3.
C) Move the instances to a public subnet.
D) Increase the instance size.
Correct Answer: B
Explanation: A Gateway VPC endpoint for S3 routes S3 traffic privately within AWS at no per-GB charge, bypassing the NAT Gateway and eliminating its data-processing fees for S3 access. (A) adds cost. (C) weakens security and may still incur transfer costs. (D) doesn’t affect NAT charges.