Correct option is D
Design: Consists of a worm (screw-like gear) meshing with a worm wheel (helical gear).
Shaft Orientation: Typically transmits motion between shafts at 90° angles that are non-intersecting.
Advantages:
High gear ratio (e.g., 20:1 to 300:1) in a compact space.
Smooth and quiet operation.
Self-locking capability (worm can drive the wheel, but wheel cannot reverse-drive the worm).
