What tool position is used when only a minimum degree of volume is desired?

The correct choice is the off base tool position. When utilizing the off base position, the tool is placed at the lowest area of the base, which allows for the hair to lay flatter against the scalp. This positioning minimizes lift and creates a more subtle volume effect, making it ideal when only a minimum degree of volume is desired.

This technique is particularly useful for clients who want a softer appearance, as it provides a smoother finish without excessive bounce or fullness. In contrast, other tool positions, such as on base or half off base, are designed to create more significant volume and lift by positioning the tool higher on the base. Each positioning technique serves a distinct purpose in achieving different styles and effects in hair design.