What should you do when there is a blank traffic light at an intersection?

• You must yield the right-of-way to the vehicles already in the intersection.
• You must yield the right-of-way to the vehicles entering the intersection from your right side.
• You must come to a complete stop.
• Both A & B
  Explanation:

  "During an electrical power loss, traffic lights at intersections will not work. Yield the right-of-way to vehicles in the intersection and to vehicles entering the intersection from your right. Go cautiously and use the intersection the same way you would use an intersection with all-way stop signs."