You are approaching the crest (top of a hill) on a narrow road, the safest procedure is to:

• A. Increase your speed and sound your horn.
• B. Flash your headlights to warn oncoming traffic.
• C. Keep to the left and slow down.
  Explanation:

  "Keeping to the left gives other vehicles more room, and slowing down ensures that if you reach the crest and see a previously hidden obstacle on the other side you have more time to stop."