Ontario's demerit schedule has exactly one offence worth five points, and it does not apply to ordinary drivers at all. What is it?

Correct answer: A. Failing to stop at an unprotected railway crossing — an offence listed for bus drivers only

Failing to stop at an unprotected railway crossing — and the entry is marked "for bus drivers only". It sits alone in the five-point tier, between the six-point group (careless driving, racing, failing to stop for a school bus, and the worst speeding tiers) and the four-point group (following too closely, failing to stop at a pedestrian crossover, and speeding 30 to 49 km/h over). The reason a bus draws a heavier penalty than a car for the same manoeuvre is the same reason the Highway Traffic Act makes bus drivers stop at crossings without gates or lights in the first place: a bus full of passengers stalled on a track is a different order of consequence.

Source: MTO Driver's Handbook: Understanding demerit points (ontario.ca) — five-point offences