<prompt> Which of the following is produced by Argentaffi- noma of ileum?G.A.B.A.SerotoninEpinephrineNor-epinephrine  <response>: Ans. b i.e. Serotonin o Argentaffin cells of the carcinoid produce serotonin.o The metabolites of serotonin are 5HIAA and are used in the diagnosis of carcinoid syndrome. 