Challenge: Lighting and reflection of the trailer

Every light sounds like 'just mandatory' — and that is what the CBR exam designer counts on. In reality three colours are always fixed (red rear, white front, orange side), but three lights each hang on their own threshold: width 1.60 m, weight 750 kg, length/width 6 m or 2.10 m. Anyone who mixes up those thresholds falls for every 'shouldn't it have that?' trap. Once you know which light belongs to which condition, you see straight through it.