Which type of motor can reverse direction by physically changing the position of its stator poles?

The correct choice reflects the fact that shaded-pole motors are specifically designed to allow for reversal of direction by physically altering the position of the stator poles.

In a shaded-pole motor, the stator consists of a single winding with a shaded area that creates a phase difference in the magnetic field. By manipulating the arrangement of these shaded portions, it is possible to change the magnetic field direction, which, in turn, reverses the rotational direction of the rotor. This feature is particularly effective in low-power applications where simple control is adequate.

While inductive, universal, and hysteresis motors can have their direction of rotation changed, they do so through different means—typically, by swapping connections or using different types of commutation rather than by physically moving parts of the stator. This distinction highlights the unique operational principles of shaded-pole motors that allow for direct physical reconfiguration of the stator to achieve directional change.