Is it permitted to drive the car on a public road?
“If a motor vehicle or a vehicle coupled to this has a load where either side protrudes more than 20 centimetres outside the vehicle, or if the vehicle’s width, including load, exceeds 260 centimetres, [...] the vehicle or a vehicle coupled to this may only be driven on a private road.” (Road Traffic Ordinance)
Review of the options:
No, as the width is 260 cm. – Wrong, the width may be exactly 260 cm, but not more.
No, as the load protrudes 40 cm on one side. – Correct, according to the quote from the Road Traffic Ordinance.
Yes, as the width does not exceed 260 cm. – Wrong, as this answer implies that it is permitted to drive the car with this load.
Yes, as the load does not protrude at all on the other side. – Wrong, as this answer implies that it is permitted to drive the car with this load.