A system administrator has a two-disk volume group （testvg） with one logical volume （testlv） which has just been mirrored across both disk drives. Which of the following commands can be used to turn off quorum？（）

• A、chvg -Qn testvg
• B、chlv -Qn testlv
• C、varyoffvg testvg； varyonvg -Qn testvg
• D、varyoffvg testvg； exportvg testvg； importvg -Qn testvg； varyonvg testvg