At an intersection, motorcycle A is on a priority road curving right. Car B is on the priority road curving left into motorcycle A's oncoming lane. Car C is on a subordinate side road with a STOP sign. What is the order of passage?

1. Motorcycle A and Car B first (with Motorcycle A having priority over Car B because a left-turning vehicle must yield to oncoming traffic), then Car C last
2. Car C first, then Motorcycle A, then Car B
3. Car B first because it is a car, then Motorcycle A, then Car C
4. All three vehicles have equal right-of-way and must proceed together