What precautions should you take when driving through fog?

• You should make sure that you are driving slowly enough.
• You should leave a safe braking distance between you and the vehicle ahead.
• You should move off the road if the visibility is decreasing further.
• All of the above.
  Explanation:

  "In a fog, you should: 1) Watch your speed. You may be going faster than you think. If so, reduce speed gradually. 2) Leave a safe braking distance between you and the vehicle ahead. 3) Not stop on the road. If visibility decreases rapidly, pull off the road into a safe parking area and wait for the fog to lift."