Before you can create a session policy in Microsoft Defender for Cloud Apps (MCAS), you must enable real-time session control integration through Conditional Access. This is achieved by creating a Conditional Access policy that uses the "Use Conditional Access App Control" session control option.
As explained in SC-300's "Manage Cloud App Security integration" module, Conditional Access policies are the gateway for routing session traffic through Defender for Cloud Apps for monitoring or control.
Options A, C, and D in the question represent post-deployment or reporting tasks, not the initial configuration step needed to enable session control.
# Correct Answer: B. From the Microsoft Entra admin center, create a Conditional Access policy.