An organization plans to migrate to Office 365.
You need to estimate the post-migration network traffic.
Which tool should you use?

A.
Microsoft Online Services Diagnostics and Logging (MOSDAL) Support Kit

B.
Microsoft Network Monitor

C.
Lync 2013 Bandwidth Calculator

D.
Microsoft Remote Connectivity Analyzer

Explanation:

http://technet.microsoft.com/en-us/library/hh852542.aspx
Lync 2013 Bandwidth Calculator – is the only tool that can estimate , the rest just monitor actual trafic
Office 365 includes Lync 2013.
With this latest version of the Microsoft Lync Server 2010 and 2013 Bandwidth Calculator, you can enter information about your users and the Lync Server features
that you want to deploy, and the Bandwidth Calculator will determine bandwidth requirements for the WAN that connects sites in your deployment. The
accompanying Bandwidth Calculator User Guide describes the recommended process for estimating your WAN bandwidth needs for Lync client real-time traffic.
Lync Server 2010 and 2013 Bandwidth Calculator Version 2.0 http://blogs.technet.com/b/nexthop/archive/2013/06/07/lync-server-2010-and- 2013-
bandwidth-calculator-version-2-0.aspx