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
Length of alimentary canal from oral cavity to gastro esophageal junction is- 
Select and explain. 
A. l5cm, B. 25 cm, C. 30 cm, D. 40 cm
D: 40 cm
Answer: D: 40 cm 
Explanation: None