What should we do when driving behind a vehicle that is giving a direction indicator signal?

1. A Stay close to the right of the road.
2. B Continue driving without slowing down. It has nothing to do with you.
3. C Continue driving at an accelerated speed, to minimize the conflict period.
4. D We should allow the driver of the vehicle in front to perform the action he signaled for, by slowing down and stop if required.