Three Categories for Equipment-Based Services Are

Three categories for equipment-based services are

A) unskilled labor, those operated by relatively unskilled operators, and self-serve.
B) professionals, those operated by relatively unskilled operators, and automated.
C) automated (self-serve) , those operated by relatively unskilled operators, and those operated by skilled operators.
D) unskilled labor, skilled labor, and professionals.
E) those operated by skilled operators, unskilled labor, and professionals.