When passing a cyclist in a bus, you should where practical give them a distance gap of at least...?

Answer: A — 1 metre

Passing a cyclist in a bus can be dangerous, so it's important to give them enough space for their safety and yours. Options B and C are incorrect because they are smaller distances than option A. Option D is incorrect because it is larger than option A. While option A may still be a close distance, it is considered the minimum safe distance to give to a cyclist when passing in a bus. This ensures that there is enough space for the cyclist to maneuver, in case of any sudden movements or road obstacles.