Which safety check must be performed immediately prior to turning the ignition key or pressing the start button?

1. Engage first gear and release the footbrake completely
2. Switch on high beam headlights and hazard warning flashers
3. Confirm the gear lever is in Neutral (manual) or Park/Neutral (automatic) and the handbrake is firmly engaged
4. Depress the accelerator pedal to the floor to prime the fuel pump