Overall optimum degree of taper of tooth preparation for maxillary anterior tooth is:: (A) 6 degrees, (B) 10 degrees, (C) 14 degrees, (D) 19 degrees
Answer is B. For anterior preparations, 10 degree taper is recommended.
For cast preparations, 6 degree taper is optimum.

Ref: Stephen Rosenstiel, Martin Land, and Junhei Fujimoto, Contemporary Fixed Prosthodontics 5th Edition