This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Preoperative assessment and monitoring in anaesthesia, Subject name: Anaesthesia
The BEST indication of a difficult intubation in morbid obesity: 
Select and explain. 
A. Mallampatti Score, B. Neck circumference, C. Limited neck movement, D. Body weight
B: Neck circumference
Answer: B: Neck circumference 
Explanation: Factors looked at included: "height, weight, neck circumference, width of mouth opening, sternomental distance, thyromental distance and Mallampati score" * "Logistic regression identified neck circumference as the best single predictor of problematic intubation.In patients with a large neck, the view during direct laryngoscopy was poorer."