What is the most likely cause of this problem?

Refer to the exhibit.

An engineer wants to setup a mobility anchor for the Guest WLAN, but does not see the Anchor IP address listed in the drop-down.

What is the most likely cause of this problem?
A . The mobility anchor is currently unreachable.
B . The mobility anchor must also be included in the mobility group of the WL
D . Layer 3 Security must be configured for Web Policy Authentication.
E . The mobility anchor is attached to another WLA
G . Layer 3 Security must be configured for Web Policy Passthrough.

Answer: B