Explanation:

To integrate Microsoft Defender for Cloud Apps (MCAS) with Microsoft Sentinel , Microsoft's official SecOps and Sentinel documentation specifies a two-step configuration process.
* In the Defender for Cloud Apps portal - You add a security extension to enable integration with external SIEM platforms. This action allows MCAS to forward its alerts, activities, and discovered app telemetry to other Microsoft or third-party security platforms. By adding the security extension , Defender for Cloud Apps is authorized to send data streams and alerts to Microsoft Sentinel through a supported API connection.
* In Microsoft Sentinel (Azure portal) - You then add a data connector . Data connectors in Sentinel are predefined integration pipelines that bring in telemetry from Microsoft or external security solutions. The Microsoft Defender for Cloud Apps connector specifically ingests MCAS alerts and audit logs into Sentinel, where they can be correlated with other Microsoft Defender XDR signals, enabling unified detection and investigation across identity, endpoint, and cloud layers.
This integration approach adheres to Microsoft's principle of minimizing administrative effort by using native connectors rather than custom ingestion or log collector configurations. Once connected, Sentinel automatically normalizes MCAS alerts into its SecurityAlert and CloudAppEvents tables for rule creation, playbook automation, and incident correlation.
Therefore, the verified correct configuration is:
* Defender for Cloud Apps: Add a security extension
* Sentinel: Add a data connector