A cloud service provider (CSP) offers various data storage options to its customers. A customer needs to store highly sensitive financial data with strict regulatory compliance requirements. Which of the following storage options offered by the CSP would be MOST appropriate? A. Object storage, offering high scalability and cost-effectiveness for unstructured data. B. Ephemeral storage, providing temporary storage for short-lived workloads. C. Block storage with server-side encryption and customer-managed encryption keys, providing granular control and enhanced security. D. File storage with access control lists (ACLs) for basic access management.