For the weekly market in Deventer you load a beam onto your trailer that sticks out well over 1 m at the rear. You make the marker board for the end yourself. Which requirements must the board meet at minimum?
Red-white diagonal stripes, square, at least 50 by 50 cm
Red-white diagonal stripes, square, at least 42 by 42 cm
Blue-white diagonal stripes, square, at least 42 by 42 cm
Explanation
False — you take the usual shop size for the legal minimum. A 50 by 50 cm board is common, but the prescribed minimum for the rear board is 42 by 42 cm (Book p.229).