A: Application Proxy is a feature of Azure AD that enables users to access on-premises web applications from a remote client. Application Proxy includes both the Application Proxy service which runs in the cloud, and the Application Proxy connector which runs on an on-premises server.
You can configure single sign-on to an Application Proxy application.
E: Add an on-premises app to Azure AD
Now that you've prepared your environment and installed a connector, you're ready to add on- premises applications to Azure AD.
1. Sign in as an administrator in the Azure portal.
2. In the left navigation panel, select Azure Active Directory.
3. Select Enterprise applications, and then select New application.
4. Select Add an on-premises application button which appears about halfway down the page in the On-premises applications section. Alternatively, you can select Create your own application at the top of the page and then select Configure Application Proxy for secure remote access to an on-premise application.
5. In the Add your own on-premises application section, provide the following information about your application.
6. Etc.
Incorrect:
Not C: Conditional Access policies are not required.
Reference:
https://docs.microsoft.com/en-us/azure/active-directory/app-proxy/application-proxy-add-on- premises-application