For which site should you configure a firewall exception?

You are the Office 365 administrator for your company. Any communication to the Internet using a port other than 80 requires a unique firewall rule to be configured.

You successfully deploy Office 365 ProPlus to all users by using Click-to-Run for Office 365. Users install and activate Office 365 ProPlus.

Thirty days after activation, users report that they are unable to edit files by using any Office applications.

You need to ensure that users can edit files.

For which site should you configure a firewall exception?
A . https://activation.sls.microsoft.com
B . https://ols.officeapps.live.com/olsc
C . http://ols.officeapps.live.com/olsc
D . http://officecdn.microsoft.com

Answer: A

Explanation:

The activation.sls.microsoft.com url is needed to renew the product key approximately every 30 days for Office 365 ProPlus users.