The CISO should first determine the extent of the impact to the organization by assessing the nature and scope of the data breach, the type and sensitivity of the data involved, the potential harm to the organization and its customers, and the legal and contractual obligations of the organization and the service provider. This will help the CISO to prioritize the appropriate actions and resources to respond to the incident and mitigate the risks. The other options are possible actions that the CISO may take after determining the impact, depending on the circumstances and the outcomes of the investigation. References = CISM Review Manual 15th Edition, page 2231; CISM Review Questions, Answers & Explanations Database - 12 Month Subscription, Question ID: 1030