Which Azure service should you implement?

Your company has a hybrid solution for development and production. You have an Azure virtual network that
includes the following subnets:

You synchronize an on-premises Active Directory farm by using Azure Active Directory Connect. Employees
sign in to company facing Web Apps with their on-premises active directory passwords.
You need to allow traffic to RESTful services that require it.
Which Azure service should you implement?

A.
Active Directory

B.
Security Center

C.
Active Directory Federation Services

D.
Network Security Groups

E.
Windows Server Firewall