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: Medicine
In which of the following conditions of malabsorption, an intestinal biopsy is diagnostic - 
Select and explain. 
A. Celiac disease, B. Tropical sprue, C. Whipple's disease, D. Lactose intolerance
C: Whipple's disease
Answer: C: Whipple's disease 
Explanation: None