Think of the metal speeding up as it gets squeezed thinner while passing between the rolls, going from a slower speed at entry to a faster speed at exit, while the rolls themselves spin at one fixed surface speed. Near the entry, the rolls are moving faster than the metal, so friction drags the metal forward into the gap. Near the exit, the metal is now moving faster than the roll surface, so friction has to act backward to resist that relative sliding. Somewhere in between, metal speed exactly matches roll speed, there is no sliding at all, and friction has nothing to act on, so it flips direction right at that point. That crossover plane is the neutral point, defined by the reversal of friction direction, option (A).