Which combination of actions should a solutions architect take to meet these requirements?

Explanations:

Drift detection helps identify changes in the resources compared to the CloudFormation template, but it does not provide insight into how proposed changes will affect running resources. It’s more about verifying the current state against the expected state rather than understanding the impact of upcoming changes.

AWS Config tracks resource configurations and changes over time, but it doesn’t directly relate to the specific impact of changes in CloudFormation stacks or provide a way to manage resources separately. It is more about compliance and monitoring rather than managing changes effectively in this context.

Creating change sets in CloudFormation allows the solutions architect to preview changes before they are applied. This helps in understanding the potential impacts of modifications on the existing resources, allowing for informed decisions.

While creating nested stacks can help separate application and network layers, it doesn’t inherently provide visibility into the impact of changes on running resources or manage them as separate entities effectively. This option is more about organizing the stacks rather than assessing impacts.

Using cross-stack references to export outputs from the company-level VPC stack and import them into the application stack enables clear management of separate entities (application and network). This allows the application stack to be updated independently while ensuring it still references the necessary network components correctly, thereby minimizing potential impacts during migration.