The correct option is A Relapsing fever
Amoebiasis or Amoebic dysentery is the infection caused by the protozoan, Entamoeba histolytica. It belongs to the Genus: Amoeboid protozoans. Entamoeba causes infection in the large intestine of Human beings. Its symptoms are constipation, abdominal pain, cramps & stools with excess mucus and blood clots. From all the given options, Relapsing fever is the odd one out. Thus, Option A is the correct option.