At a Stop sign, what must a bus driver do?

1. Stop completely at the stop line, or at the proper point if there is no line, then proceed when safe
2. Reduce to walking pace at the line and stop when traffic is visible on the road being entered from either direction
3. Treat the sign as Give Way when the bus is on a scheduled service and the junction appears clear
4. Stop beyond the line where the driver's view improves, even if the bus enters the crossing path