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: Surgery
Following fistulous conditions give rise to maximum fluid and electrolyte imbalance - 
Select and explain. 
A. Distal ileal, B. Gastric, C. Duodenal, D. Sigmoid
C: Duodenal
Answer: C: Duodenal 
Explanation: • Enterocutaneous fistulas are classified according to their location and volume of daily output.
• These factors dictate both treatment and morbidity and mortality rates.
• In general, the more proximal the fistula in the ‘intestine’ (but not the stomach), the more serious the problem, with greater fluid and electrolyte loss.
• Maximum fluid and electrolyte imbalance occur in duodenal fistulas