Select the answer that correctly completes the sentence.

In Microsoft’s Security, Compliance, and Identity materials, Azure AD B2B collaboration is the feature designed for working with external organizations. Microsoft describes it as follows: “Azure AD B2B collaboration allows you to securely share your company’s applications and services with guest users from any other organization, while maintaining control over your own corporate data. Guest users sign in with their own work, school, or social identities, and appear as guest users in your directory.” This directly matches the sentence in the prompt—enabling collaboration with suppliers, partners, and vendors while ensuring that external users appear as guest users in the tenant.

By contrast, Active Directory Domain Services (AD DS) is an on-premises directory service for Windows domain joined resources and does not provide cloud guest user collaboration. Active Directory forest trusts establish trust relationships between AD DS forests for resource access, not modern cloud guest access using Conditional Access, MFA, or entitlement processes. Azure AD B2C is for consumer/retail scenarios where you build customer-facing apps, managing their identities in a separate customer directory; it is not intended for partner collaboration within your enterprise tenant. Therefore, the capability that fits the statement—external partner collaboration with users appearing as guest accounts—is Azure AD B2B.