The IAM Identity Domain Premium type is Oracle's comprehensive, full-featured Identity-as-a-Service (IDaaS) solution. It encompasses all features available in the Free and Oracle Apps Premium tiers and adds advanced capabilities. These include Identity Governance for access reviews and requests, advanced multi-factor authentication (MFA) options like FIDO2, adaptive security, and extensive third-party application integration. This tier is designed for enterprise-wide identity and access management, providing the most complete set of features for complex security and compliance requirements.

A. External User: This is a license model for managing B2B and B2C users within a domain, not a distinct domain type itself.

C. Free: This is the default, basic tier included with an OCI tenancy. It provides core identity functions but lacks the advanced security and governance features of a full IDaaS solution.

D. Oracle Apps Premium: This domain type is specifically tailored for Oracle Applications (like Fusion Cloud Apps) and, while feature-rich, is superseded by the Premium type, which is the most comprehensive offering.

1. Oracle Cloud Infrastructure Documentation, "IAM with Identity Domains," Section: "Understanding Identity Domain Types."

Reference Detail: The documentation explicitly states, "The Premium domain type is a full-featured Identity-as-a-Service (IDaaS) solution. The Premium domain type includes all the features of the Oracle Apps Premium domain type, plus additional features such as Identity Governance..." This directly confirms that Premium is the correct answer. It also describes the "Free" and "Oracle Apps Premium" types as having fewer features.

2. Oracle Cloud Infrastructure Documentation, "IAM with Identity Domains," Section: "Compare Identity Domain Types."

Reference Detail: The feature comparison table in this section clearly shows that the "Premium" column has checkmarks for all available features, including "Identity Governance," "Adaptive Security," and "Identity Synchronization with On-Premises Directories," which are absent in the "Free" tier. This visually demonstrates its status as the "full-featured" option.