Explanation
Reviewing the provider's incident definitions and notification criteria is the FIRST course of action when aligning the organization's incident response capability with a public cloud service provider. This is because the organization needs to understand how the provider defines and classifies incidents, what their roles and responsibilities are, and how they will communicate with the organization in case of an incident. This will help the organization align its own incident response processes and expectations with the provider's and ensure a coordinated and effective response.