A company runs a large-scale application on a fleet of Amazon EC2 instances that are distributed across several VPCs. A Network Load Balancer (NLB) in a separate VPC routes traffic to the EC2 instances. The NLB's VPC is peered to all the application VPCs.
The application must process millions of requests each minute during times of peak utilization. Users are reporting that the connections to the application are failing during peak times. Monitoring shows an increase in port allocation errors on the NLB.
Which action will solve this issue with the LEAST change to the architecture?

A. Increase the number of EC2 instances in the target group.
B. Create an Application Load Balancer for the target group.
C. Add a new target group to the same NLB listener.
D. Change the target group type to "instance."