When vehicles meet on a steep, narrow road, not wide enough for two vehicles, which vehicle must yield the right-of-way? a. the vehicle going uphill b. the vehicle going downhill c. the vehicle going slower

B. The vehicle going downhill

Explanation: The vehicle going huphill needs more force to move, while the vehicle moving downhill actually can be moved only by the gravity acceleration.

So when both cars meet, if the car going uphill loses momentum, the vehicle may not be capable to keep moving uphill after that, so is better that the car going downhill yields the right-of-way to the other car, that needs to preserve the momentum.