Oracle Cloud Infrastructure (OCI) Identity and Access Management (IAM) is a foundational security service. Its primary purpose is to control who can access OCI resources, what type of access they have, and to which specific resources. This is central to any security and compliance framework. OCI Vault is a managed service specifically designed for security by providing centralized management of encryption keys and secrets. It helps customers protect their data with keys they control, which is a common requirement for meeting compliance standards like PCI DSS and HIPAA.

A. OCI Object Storage: This is a service primarily designed for data storage. While it has robust security features, its core function is storage, not security management.
D. OCI Networking: This service's primary function is to provide a customizable and private network. Security components like Security Lists are features, but the service's main purpose is connectivity.

1. Oracle Cloud Infrastructure Documentation, "Overview of Identity and Access Management": "Oracle Cloud Infrastructure Identity and Access Management (IAM) service lets you control who has access to your cloud resources. You can control what type of access a group of users has and to which specific resources." (Doc ID: oci-iam-overview.pdf, Section: "How IAM Works")

2. Oracle Cloud Infrastructure Documentation, "Overview of Vault": "Oracle Cloud Infrastructure Vault is a key management service that stores and manages master encryption keys and secrets for secure access to resources... Vault provides a highly available, durable, and managed service for your sensitive information." (Doc ID: oci-vault-overview.pdf, Section: "Concepts")

3. Oracle Cloud Infrastructure Documentation, "Overview of Security": This document categorizes OCI services. IAM and Vault are listed under the "Security and Identity Services" portfolio, confirming their primary design purpose. In contrast, Networking and Storage are listed under core "Infrastructure" services. (Doc ID: oci-security-overview.pdf, Section: "Security and Identity Services")