According to the law an accordian style bus:

1. Correct answer: Is obliged to display rectangular stickers on rear wall of the bus .
2. Is obliged to display two stripes on the rear wall of the bus 4X100 cm.
3. Is obliged to display Stickers and stripes.
4. Is obliged to display two reflecting stripes and writen on them "keep distance".

WhyAn articulated bus must have rectangular reflective stickers on its rear. The law does not require a 'Keep your distance' inscription.