What should be the first step to ensure Windows 11 Enterprise multi-session hosts in Pool1 are hybrid Azure AD-joined?

To ensure that Windows 11 Enterprise multi-session hosts are hybrid Azure AD-joined, the first step involves joining the session hosts to Active Directory Domain Services (AD DS). This process is essential because it allows the machines to be part of the on-premises Active Directory environment, which is the foundation for establishing a hybrid identity setup.

Once the session hosts are joined to AD DS, they can then be registered with Azure AD, which is vital for achieving hybrid Azure AD join. This two-step process is crucial as it ensures that the devices are managed both on-premises and in Azure, allowing for seamless integration and management of resources. Joining the session hosts to AD DS establishes their identity in the domain, which is a prerequisite for further configuration required for hybrid scenarios.

Other options focus on either directly joining the session hosts to Azure AD, which would not yield a hybrid configuration, or referencing Azure AD Domain Services, which operates differently and may not be necessary in this context. Thus, initiating the process by joining the session hosts to AD DS is the correct and necessary first step.