What can the company do to find out how the changes will impact the resources that are running?

Explanations:

Change sets allow you to preview the changes that will be made to the resources when updating a stack. This provides insight into how the resources will be impacted by the changes before executing them.

Stack policies are used to control the actions that AWS CloudFormation can perform on resources during stack updates. They do not provide information about how changes will impact the resources.

The Metadata section in a CloudFormation template contains arbitrary information that can be used by tools or scripts, but it doesn’t provide information on how changes will impact resources.

The Resources section lists the resources being created, modified, or deleted, but it does not provide a direct preview of how changes to the stack will affect these resources. Change sets are the appropriate tool for this.