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
Acute mechanical large bowel obstruction should be operated early because of the risk of ? 
Select and explain. 
A. Respiratory embarrassment due to abdominal distension, B. Electrolyte imbalance from vomiting, C. Septicaemia from bowel contents, D. Closed-loop obstruction and caecal perforation
D: Closed-loop obstruction and caecal perforation
Answer: D: Closed-loop obstruction and caecal perforation 
Explanation: Ans. 'd' Closed-loop obstruction and cecal perforation