<prompt> Most common site of gastrointestinal carcinoid is -DuodenumAppendixIleo-JejunumStomach  <response>: Answer- C. Ileo-JejunumCarcinoid tumors arise from the neuroendocrine cells Argentaffin cells or Kulchitsky cells.The majority are found in GI tract, and more than,l0 in small intestine jejunum ileum.The tracheobronchial tree and lungs are the next common sites involved. 