Which point defines the positive X direction in a USER FRAME?

• A. XY point
• B. Origin Point
• C. A point on the positive X-axis
• D. XX point

Answer: (D)

In a USER FRAME, the location comes from the origin, but the direction of each axis is set by a reference point that defines that axis’s positive sense. The XX point is the designated reference used to establish the positive X direction from the origin, giving a clear vector for the X axis. An origin fixes position but not orientation; a point on the positive X-axis can indicate the line, but the system uses the XX point as the explicit reference to lock in the positive X direction. The other options either don’t provide that explicit axis-defining reference or describe only the location or a generic point on the axis, not the formal mechanism used to define direction.