Yield when: narrow road + obstacles + vehicle going downhill give way to uphill.
Answer 3 is incorrect because vehicle going uphill gives way to vehicle downhill.
Where the road is narrow enough for only one vehicle to run and there is a place to avoid the vehicle, the vehicle closest to the avoidance must enter the avoidance position and give way to the other vehicle.
Vehicles going downhill must give way to vehicles going uphill; vehicles with obstacles ahead must give way to vehicles without obstacles in front.
Vehicles going uphill must give way to vehicles going downhill.