What should you do when approaching a roundabout?
Answer: A — Slow down and yield to traffic in the roundabout.
Approaching a roundabout, you should always slow down and yield to traffic in the roundabout. This allows for a smooth and safe flow of traffic. Option B is incorrect because speeding up can lead to accidents or cause other drivers to slow down suddenly. Option C is incorrect because coming to a complete stop is not necessary unless there is oncoming traffic. Option D is incorrect because honking your horn can startle other drivers and is considered unnecessary and rude.