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
Earpiece type face bow: All are true, except: 
Select and explain. 
A. Its an arbitrary type facebow, B. External auditory meatus is considered as reference point to determine centre of condylar rotation, C. It is difficult to manipulate, D. None of the above
C: It is difficult to manipulate
Answer: C: It is difficult to manipulate 
Explanation: Earpiece type (ear bow): In this type, the external auditory meatus is considered as reference point to determine the centre of condylar rotation.
The condyles are located at an approximate distance in front of the meatus and this is compensated in the articulator, by mounting the facebow behind the condylar centre.
This type of facebow is easier to manipulate clinically.