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 “Position” of proximal locks refers to: 
Select and explain. 
A. Direction of movement of the axis of the bur, B. The occlusal height of the lock, given a constant depth, C. The axiofacial and axiolingual line angles of initial tooth preparation, D. The extent of translation
C: The axiofacial and axiolingual line angles of initial tooth preparation
Answer: C: The axiofacial and axiolingual line angles of initial tooth preparation 
Explanation: There are four characteristics or determinants of proximal locks:

Position.
Translation.
Depth.
Occlusogingival orientation.


Position refers to the axiofacial and axiolingual line angles of initial tooth preparation (0.2 mm axial to DEJ). It is important to note that the retention locks should be placed 0.2 mm inside the DEJ, regardless of the depth of the axial walls and axial line angles.
Translation refers to the direction of movement of the axis of the bur. 
Depth refers to the extent of translation (i.e., 0.5 mm at gingival floor level). 
Occlusogingival orientation refers to the tilt of the No. 169L bur, which dictates the occlusal height of the lock, given a constant depth.

Reference: Sturdevant operative dentistry. 4th edition, Page No:705