When you wish to drive straight ahead at a roundabout you may enter from either the left or right lane. As you continue around you should:

• A. Change lanes to get through quickly.
• B. Keep in the lane you entered the roundabout.
  Explanation:

  "If the lanes are marked so that you can go straight ahead from either, then you can, as long as you stay in the same lane as when you entered the roundabout. Signal left once you've passed the exit before the one you are taking."
• C. Move into another lane with least traffic.