(C) Cryptosporidium parvum (correct) vs (E) Giardia lamblia (incorrect)

There are three main protozoa that cause GI infections:

• Giardia lamblia - which causes fatty, foul-smelling stools, is transmitted via cysts in water (usually unfiltered river or lake water), and on histology, shows a flagellated, pear-shaped trophozoite with two large, central nuclei
• Entamoeba histolytica - which causes bloody diarrhea or dysentery, liver abscesses, RUQ pain, and presents with flask-shaped ulcers on colon biopsy
• Cryptosporidium - which causes watery diarrhea in immunocompetent hosts and severe diarrhea in AIDS patients, transmits via oocysts in water, and is an AIDS-defining illness (happens at CD4+ < 100/mm3)