Which of the following alternatives will replace the question mark?

Ignition, Acceleration, Motion, Deceleration, ?

The correct option is Stop.

To solve this sequence puzzle, let us examine the logical progression of events related to driving or operating a motor vehicle:

1. Ignition – Starting the vehicle's engine.
2. Acceleration – Increasing the speed of the vehicle to get it moving.
3. Motion – The ongoing movement or travel of the vehicle.
4. Deceleration – Slowing down the speed of the vehicle.
5. Stop – Bringing the vehicle to a complete halt.

Each term represents a sequential state or action in the full lifecycle of a vehicle's trip from start to finish. Following "Deceleration" (slowing down), the next and final chronological step is coming to a complete Stop.

Therefore, the question mark (?) should be replaced by Stop.