This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Pediatrics
Profuse watery diarrhoea in an immune compromised child is due to 
Select and explain. 
A. Cryptococcus, B. Amoeba, C. Giardia, D. Lactose intolerance
C: Giardia
Answer: C: Giardia 
Explanation: Giardiasis caused by Giardia lamblia is a major cause of diarrhoea in children and travellers. Individuals with malnutrition,humoral immunodefeciencies,and cystic fibrosis are particularly susceptible.
Features: acute diarrhoea with sudden onset of explosive, watery foul smelling stools, along with nausea and anorexia,abdominal distension,flatulence,epigastric camps and mild fever.