How should vehicle drivers conduct themselves while driving on a road with a narrow and steep hill..

1. A The driver of the descending vehicle shall, if required, stop his vehicle and make way for the ascending vehicle
2. B The driver of the ascending vehicle shall, if required, stop his vehicle and allow the descending vehicle to continue driving.
3. C First one to arrive is first to enter into the narrow section.
4. D It is sufficient that they both deviate to the right, onto the roadway’s edge, to prevent collision.