Which movement is more useful for making a long free line?

Correct answer: Shoulder and whole-arm movement

The governing concept is using the appropriate body movement for line length. A long freehand line needs a broad, continuous sweep, so movement from the shoulder and whole arm gives better reach and steadier flow. Thus, option B is correct. Small finger movements are useful for short details, but they cannot comfortably produce a long fluid stroke; foot and head movements are not drawing techniques.