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: Dental
The maximum depression of the soft palate is recorded when Frankfort horizontal plane is 
Select and explain. 
A. 30° below the horizontal plane, B. 10° below the horizontal plane, C. 60° below the horizontal plane, D. 80° below the horizontal plane
A: 30° below the horizontal plane
Answer: A: 30° below the horizontal plane 
Explanation: None