The origin of the workpiece coordinate system in CNC machining is generally specified by the programmer according to the actual situation of the workpiece.
That is to say, the origin of the coordinate system of the CNC machining workpiece is determined by the manufacturer and can be changed by the user. So the answer to this question is B .
Usually the origin of the workpiece coordinate system is set at a specific point on the workpiece, such as the zero point of the workpiece or a specific hole center point on the workpiece.
The position of this origin is specified in the program and calibrated with the actual workpiece before machining to ensure accuracy and precision in machining.