Which of the following is required In order to achieve free/busy interoperability between Google and Microsoft Exchange?
- Exchange web services must be opened on port 443 for https://calendar.google.com
- Exchange web services must be opened on port 443 for all of Google’s IPv6 net blocks
- Exchange web services must be opened on port 443 for all of Google’s IP blocks
- Exchange web services must be opened on port 443 for a small subset of Google’s IP blocks