In which gear will a bus start moving forward in good road conditions, on a flat surface?

In the photo you can see the gear lever in a bus, and next to it a sticker saying "Anfahren nur im 1. Gang", which means "move off only in 1st gear". On level ground you start driving forward in the lowest gear specified by the manufacturer - answer A.

The Road Traffic Act requires you to drive at a speed that ensures control over the vehicle, and the vehicle itself must be maintained so that using it does not endanger safety. The manufacturer knows in which gear the engine and the clutch can move a heavy bus off without overload - and that is exactly what the sticker in the photo means. Moving off in third gear (answer B), even in an empty bus, overheats the clutch and wears it out quickly. "First gear of the upper range" (answer C) is, in a gearbox with a range change, a high gear in which the bus could move off only with a lot of clutch slip. That is why you always start in the gear that the manufacturer's manual shows.

Legal basis: Art. 19 para. 1 and Art. 66 para. 1 point 1 of the Road Traffic Act (Prawo o ruchu drogowym)