Which three actions should you perform?

You have an Exchange Server 2013 organization.
A new policy requires that all iPhone users access their on-premises mailbox by using the OWA for
iPhone app.
You need to ensure that push notifications for the OWA for iPhone app are configured before the
users install the app.
Which three actions should you perform? Each correct answer presents part of the solution.

A.
Configure Microsoft Azure Active Directory Sync (Azure AD Sync).

B.
Modify the EWS virtual directory.

C.
Enable push notifications proxy.

D.
Enroll in Microsoft Office 365 for business.

E.
Modify the OWA virtual directory.

F.
Set up on premises Exchange 2013 to Office 365 Authentication.