which way do components of the NAC Appliance architecture communicate?

In which way do components of the NAC Appliance architecture communicate?

A.
NAC Appliance Manager sends check-up instructions to the NAC Appliance Server.

B.
NAC Appliance Manager sends remediation instructions to the NAC Appliance Agent.

C.
NAC Appliance Server sends block instructions to the NAC Appliance Agent.

D.
NAC Appliance Agent sends procedure instructions to the NAC Appliance Server.

E.
NAC Appliance Agent sends check-up instructions to the NAC Appliance Manager.

F.
NAC Appliance Server sends block instructions to the NAC Appliance Manager.