<prompt> Smallest helminth among the following is:Hymenolepis diminutaHymenolepis nanaDiphyllobothrium latumBalantidium coli  <response>: Smallest helminth among the following is H nana also known as dwarf tapeworm with adult length of 15-44 mm. H. diminuta also known as rat tapeworm has a length of 20-60 cms. Balantidium coli is a large ciliated protozoan 50-130 um and width 20-70 um Diphyllobothrium latum can reach upto 30 fts. 