AWS Certified Database – Specialty – Question148

A company hosts an internal file-sharing application running on Amazon EC2 instances in VPC_A. This application is backed by an Amazon ElastiCache cluster, which is in VPC_B and peered with VPC_A. The company migrates its application instances from VPC_A to VPC_B. Logs indicate that the file-sharing application no longer can connect to the ElastiCache cluster.
What should a database specialist do to resolve this issue?

A.
Create a second security group on the EC2 instances. Add an outbound rule to allow traffic from the ElastiCache cluster security group.
B. Delete the ElastiCache security group. Add an interface VPC endpoint to enable the EC2 instances to connect to the ElastiCache cluster.
C. Modify the ElastiCache security group by adding outbound rules that allow traffic to VPC_B's CIDR blocks from the ElastiCache cluster.
D. Modify the ElastiCache security group by adding an inbound rule that allows traffic from the EC2 instances' security group to the ElastiCache cluster.

Correct Answer: C