Which protozoan is associated with the ability to cause severe dysentery?

Giardia lamblia

Cryptosporidium hominis

Cyclospora cayetanesis

Entamoeba histolytica

Entamoeba histolytica

Explanation:

Entamoeba histolytica is the causative agent of amebiasis (amebic dysentery). The pathogen enters the human body through consumption of contaminated water or food and enters the small and large intestines. E. histolytica targets the epithelium of large intestine and creates ulcers in it. E. histolytica enter the mucosa and submucosa of the intestine through these ulcers and leads to severe dysentery, that is amoebic dysentery.