The answer is reverse backhand. Milady names exactly three positions and strokes used in facial shaving — freehand, backhand, and reverse freehand — which leaves reverse backhand as the one not used for this particular service.
Reverse backhand isn't a made-up distractor — the book defines it elsewhere as the position used by right-handed barbers for shaving the left side of the neck behind the ear (and by left-handed barbers on the opposite side). It's a real stroke, just reserved for neck shaving rather than the face.
Milady Standard Barbering, 6th ed., Ch. 13 (Shaving and Facial-Hair Design), p. 342: "The three positions and strokes used in facial shaving are freehand, backhand, and reverse freehand."
This is 1 of the real Shaving questions in FadeJunkie's Milady-sourced 300-question bank. See the Shaving practice questions page for a fuller sample, or try the Shaving practice quiz and flashcards for free. A one-time $15 lifetime pass unlocks the complete question bank across all 13 tested topics.
More real Shaving questions with sourced answers: What Kind of Skin Makes Beard Hair Easier to Cut, What Beard Style Fills Out a Narrow Jaw, What Does Finishing a Shave Include, What Condition Should the Skin Be in While Shaving, and 10 more on the Shaving practice questions page.
Browse every topic on the Practice Question Hub, or see the Texas Barber State Board Exam Guide for the full exam process — required hours, PSI scheduling, and fees.