What is the most likely reason for the TIBCO Adapter status being "Unknown" and the ActiveMatrix BusinessWorks engine status being "OK" in the TIBCO Administrator console?

Two machines, Ml and M2, belong to the same domain. A TIBCO ActiveMatrix BusinessWorks engine is deployed on Ml, and a TIBCO Adapter is deployed on M2. The TIBCO Administrator server is hosted on Ml.

What is the most likely reason for the TIBCO Adapter status being "Unknown" and the ActiveMatrix BusinessWorks engine status being "OK" in the TIBCO Administrator console?
A . The TIBCO Administrator server is down.
B . On M2, the TIBCO Hawk Agent is down.
C . The TIBCO Adapter is down.
D . The domain’s messaging transport is down.
E . On Ml, the TIBCO Hawk Agent is down.

Answer: B