This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Pre Anesthetic Evaluation, Subject name: Anaesthesia
What difficulty is assessed by Mallampati score/classification- 
Select and explain. 
A. Inadequate mouth opening, B. Sho and thick neck, C. Long upper incisors, D. Large tongue
D: Large tongue
Answer: D: Large tongue 
Explanation: The Mallampati classification has become standard for assessing the relationship of the tongue size relative to oral cavity. from class 1 to 4 gradually tongue size is increasing.