You have an Exchange Server organization. The organization contains a server named EX01 that has
Exchange Server 2010 installed and a server named EX02 that has Exchange Server 2013 installed.
Your mailbox is hosted on EX01.
You need to access the Exchange Admin Center (EAC).
Which URL should you use?

A.
https://EX01/ecp?ExchClientVer= 14

B.
https://EX02/ecp?ExchClientVer= 15

C.
https://EX02/eac?ExchClientVer=15

D.
https://EX01/ecp?ExchCfientVer=15

Explanation:
http://technet.microsoft.com/en-us/library/jj150562(v=exchg.150).aspx
If you’re in a coexistence scenario, where you’re running Exchange 2010 and Exchange 2013 in the same
organization, and your mailbox is still housed on the Exchange 2010 Mailbox server, the browser will default to
the Exchange 2010 ECP. You can access the EAC by adding the Exchange version to the URL. For example,
to access the EAC whose virtual directory is hosted on the Client Access server CAS15-NA, use the following
URL: https://CAS15-NA/ecp?ExchClientVer=15. Conversely, if you want to access the Exchange 2010 ECP
and your mailbox resides on an Exchange 2013 Mailbox server, use the following URL: https://CAS14-NA/ecp?
ExchClientVer=14.