Microsoft Entra ID is Microsoft's foundational cloud-based identity and access management (IAM) service. It is designed to manage user identities (accounts and groups) and provide secure access to resources. Its core capabilities include Single Sign-On (SSO) to thousands of SaaS applications and Microsoft 365, enforcing multi-factor authentication (MFA), and implementing Conditional Access policies to govern access based on specific conditions. This makes it the central platform for the requirements described by Litware.

B. Microsoft Entra Permissions Management is a Cloud Infrastructure Entitlement Management (CIEM) solution for managing permissions in multicloud environments, not the core identity provider.

C. Microsoft Defender XDR is a security solution for extended detection and response (XDR) across the environment; it is not an identity and access management platform.

D. Microsoft Intune is a unified endpoint management (UEM) solution for managing devices and applications, not the central directory service for user identities.

1. Microsoft. (n.d.). What is Microsoft Entra ID? Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/entra/fundamentals/whatis. (See the "Who uses Microsoft Entra ID?" and "What are the Microsoft Entra licenses?" sections.)

2. Microsoft. (n.d.). Application management with Microsoft Entra ID. Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/entra/identity/app-mgmt/what-is-application-management. (This document details the SSO capabilities.)

3. Microsoft. (n.d.). What is Conditional Access in Microsoft Entra ID? Microsoft Learn. Retrieved from https://learn.microsoft.com/en-us/entra/identity/conditional-access/overview. (This document explains how Conditional Access works as a feature of Entra ID.)