The singer plays the essential role because______ .

• A. 
   she accompanies the other musicians with the “phach”, an instrument made of wood or bamboo
• B. 
  she makes the drummer shows his approval of the singer or the songs by hitting the side of the drum twice
• C. 
  the drummer only shows his approval or disapproval to the song and the “dan day“ player must follow the rhythm of the drummer
• D. 
  the “dan day” player must follow the rhythm of the “phach”, and the drummer only shows his approval or disapproval of the singer or the songs