which router will respond to client ARP requests?

In GLBP, which router will respond to client ARP requests?

A.
The active virtual gateway will reply with one of four possible virtual MAC addresses.

B.
All GLBP member routers will reply in round-robin fashion.

C.
The active virtual gateway will reply with its own hardware MAC address.

D.
The GLBP member routers will reply with one of four possible burned in hardware addresses.