Which of the following commands will set the duplex of a network adapter？（）

A.no -a media_speed=100_Full_Duplex en0

B.ifconfig -a media_speed=100_Full_Duplex ent0

C.chdev -l ent0 -a media_speed=100_Full_Duplex

D.chinet -l en0 -a media_speed=100_Full_Duplex en0