<prompt> Conservation of tooth structure during biomechanical preparation of crown can be done byUse of partial-coverage restorationsMinimum practical convergence angle taper between axial wallsPreparation of the occlusal surface, so reduction follows the anatomic planesAll of the above  <response>: Tooth structure is conserved by using the following guidelines: Use of partial-coverage rather than completecoverage restorations.Preparation of teeth with the minimum practical convergence angle taper between axial walls.Preparation of the occlusal surface so reduction follows the anatomic planes to give uniform thickness in the restoration.Preparation of the axial surfaces so tooth structure is removed evenly; if necessary, teeth should be orthodontically repositioned.Selection of a conservative margin compatible with the other principles of tooth preparation.Avoidance of unnecessary apical extension of the preparation. 