Biology · Kingdom Protista

Amoebic dysentery is caused by the protozoan parasite Entamoeba histolytica. It is transmitted in areas where poor sanitation allows contamination of drinking water and food with feces. In these areas, up to 40% of people with diarrhea may have amoebic dysentery.

Option A is incorrect because Pelomyxa palustris is a giant anaerobic/microaerobic amoeba that does not cause dysentery.
 

Entamoeba Histolytica is a parasitic protozoa of class Sarcodina that causes human dysentery. Therefore, option B is the correct answer.
 

Option C is incorrect because Trichonympha is a genus consisting of protists found in the hindgut of lower termite species as well as cockroaches that feed on wood. They have a symbiotic relationship with their hosts in where they help break down cellulose present in the wood while the host provides a favourable living environment in which they live.
 

Option D is incorrect because Trypanosoma is a protozoa that causes sleeping sickness in man.
 

Option E is incorrect because the radiolarian ooze is a protozoa of class sarcodina. It is studied by oil prospectors because the presence of certain species gives clues to possible petroleum deposits.