Simultaneous Multithreading (SMT) is enabled in a POWER6 VIO client running AIX 6.1. Which command would be used to disable it after the next operating system reboot is performed? itcert（）

A. schedo -o smt=0 -p 
B. smtctl -m off -w boot 
C. chdev -l sys0 -a smt=off 
D. echo 0 > /proc/sys/smt_enable