<prompt> Which of the following structure is preserved in Type I Modified radical neck dissection?SternocleidomastoidSpinal accessory nerveLevel IX lymph nodeInternal juglar Nein  <response>: Modified radical neck dissection involves removal of I - V lymph nodes In type 1: Spinal accessory nerve is preserved.In type 2: Internal juglar vein is preserved.In type 3: Sternocleidomastoid. 