Final answer:
Parking is illegal at a curve on the highway outside a city, town, or village when the vehicle cannot be clearly seen from at least 150 meters in each direction upon the highway.
Step-by-step explanation:
Parking at a curve on the highway outside a city, town, or village is illegal when the vehicle cannot be clearly seen from at least 150 meters in each direction upon the highway.
This regulation is in place to ensure visibility and safety for all drivers on the road and to prevent accidents caused by hidden or obstructed vehicles at curves.
Thus, the correct answer is B) 150 meters.