Which command will add ethO to the bridge xenbr0?

Which command will add ethO to the bridge xenbr0?

A.
brctl addif xenbr0 eth0

B.
brctl addbr xenbr0 eth0

C.
ifconfig add xenbr0 eth0

D.
netstat -a xenbr0 eth0

E.
if up xenbr0 -a eth0