What is a possible cause of the issue?

Your company has a Microsoft Teams Phone deployment that uses Direct Routing and a single carrier.

You deploy a new Session Border Controller (SBC) that shows as healthy in the Microsoft Teams admin center.

You place a test call over the new SBC, and the call succeeds.

When you attempt to transfer the call, the transfer fails. A portion of the SIP ladder is shown in the exhibit. (Click the Exhibit tab.)

What is a possible cause of the issue?
A . The Refer on the SBC is misconfigured.
B . notify is enabled in the SIP options of the SB
D . The carrier rejects the format of the forwarded FROM number.

Answer: B

Explanation:

Reference: https://docs.microsoft.com/en-us/microsoftteams/troubleshoot/phone-system/direct-routing/issues-with-call-transfers