A corporate environment includes Exchange Server 2010. The environment is configured as shown in the following table.

The company is planning to test a complete site failover. You have the following requirements:

* Ensure that users can connect to their mailboxes in the disaster recovery site by using Microsoft Outlook 2010.
* Minimize downtime during the site failover.
* Minimize client connectivity issues after the site failover.

You need to recommend a solution that meets the requirements.

What should you recommend?

A.
Add a DNS record pointing exchange.contoso.com to the DR-MBX1 server.

B.
Add a DNS record pointing exchange.contoso.com to the DR-HTCAS1 server.

C.
Prior to the site failover, raise the time to live (TTL) value of exchange.contoso.com to the maximum value. After the site failover, update exchange.contoso.com to point to DR-MBX1.

D.
Prior to the site failover, lower the time to live (TTL) value of exchange.contoso.com to the minimum value. After the site failover, update exchange.contoso.com to point to DR-HTCAS1.