MS-102 Deploy and manage a Microsoft 365 tenant Practice Question

Answer analysis

Option-by-option breakdown

For each option: why learners choose it and why it is or isn't the right answer here.

• ✓

  The organization relationship between the on-premises and cloud tenants is missing or misconfigured.

  Why this is correct

  In Exchange hybrid deployments, free/busy sharing depends on a specific organization relationship between the on-premises Exchange organization and the Exchange Online tenant. This relationship defines the federated trust, sharing domain, and the availability service endpoints, so if it is missing or misconfigured, the Availability service cannot resolve cross-premises calendar requests even though mail routing remains functional. The organization relationship is the control plane for calendaring, not for transport, so its absence presents exactly the symptom described: messages flow but free/busy fails. Verify the relationship's sharing domain and the Autodiscover URLs to restore availability.

• ✗

  Microsoft Entra Connect has not been configured with the correct synchronization scope.

  Why it's wrong here

  The Microsoft Entra Connect synchronization scope controls which on-premises directory objects are replicated to Microsoft Entra ID, determining who gets a cloud mailbox or a synchronized user identity. However, it does not establish the application-level trust needed for the Availability service to query calendar data across the on-premises and cloud boundaries. Even with perfect synchronization, the free/busy request would still fail if no organization relationship exists, because that relationship contains the endpoint URLs and trust identities that calendar lookups rely on. Thus, a sync scope error would cause missing users or mailboxes, not the isolated free/busy failure described in the scenario.

• ✗

  The on-premises firewall is blocking traffic to the Exchange Online endpoints.

  Why it's wrong here

  If the on-premises firewall were blocking traffic to Exchange Online endpoints, the impact would be much broader than calendar availability alone—hybrid mail transport, Autodiscover lookups, and client connections would all degrade or fail. Because the scenario states that other hybrid features, including mail flow, continue to work normally, a firewall block is an inconsistent explanation, as it would interrupt the same TCP/IP and TLS channels used by multiple Exchange services. Additionally, the organization relationship is the precise component that allows the Availability service to reach the remote endpoint; without it, the firewall is not even reached by a correctly targeted request. Therefore, a firewall issue would manifest as a general connectivity problem, not a specific free/busy issue.

• ✗

  OAuth authentication is not configured between on-premises and Exchange Online.

  Why it's wrong here

  OAuth authentication is not a prerequisite for cross-premises free/busy sharing in an Exchange hybrid topology; the organization relationship can authenticate using the federated trust and basic authentication over TLS. OAuth is typically configured for modern features like eDiscovery, message tracking, or Outlook's modern authentication, and its absence would cause those specific features to fail rather than availability lookups. In fact, free/busy sharing works fine in many hybrid environments that haven't enabled OAuth, so attributing the symptom to OAuth misconfiguration misidentifies the architectural dependency. The true dependency is the organization relationship, which handles the exchange of calendar data using its own trust mechanism.

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