Final answer:
In most instances, a 90 degree finger shear position angle is used to sculpt graduation from horizontal or diagonal parting.
Step-by-step explanation:
The correct answer is angle C) 90 degrees.
When sculpting graduation from horizontal or diagonal parting, a position angle of 90 degrees is commonly used. This angle allows for the creation of a smooth transition and a gradual change in the length of the hair. By holding the fingers perpendicular to the parting, the hair can be sculpted in a way that creates a graduated effect. For example, if you are cutting a diagonal parting and want to create a graduated effect, you would hold the fingers at a 90-degree angle to the parting. This would allow you to cut the hair at different lengths along the parting, resulting in a graduated look.