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 two blocks in the twin block functional appliance are angulated at (Or) The angle of inclined plane in clarke's twin block is 
Select and explain. 
A. 45°, B. 70°, C. 65°, D. 80°
B: 70°
Answer: B: 70° 
Explanation: "Twin - Block appliance" is the most acceptable functional appliance and was introduced by William Clark. The appliance consists of a upper and lower appliances with posterior bite blocks. The upper and lower bite blocks interlock at an 70°