What is a 'decreasing radius' curve, and how should a rider handle it?

1. A curve that gets sharper as you ride through it; you must enter slower and lean further.
2. A curve that opens up into a straightaway; you can accelerate early.
3. A curve with a downhill slope; you must apply the front brake continuously.
4. A curve that has no banked angle; you must stand up on the footpegs.