Question Author
the answer given is actually C - continue to the end of the road. We all thought that as soon as you realised your mistake, you should try to rectify it asap, either by turning into a side road or reversing into a driveway and then proceeding in the correct direction. Obviously, in a real life situation you would have to use your own judgement depending on the options open to you, but for the purposes of the theory test it looks like answer c is the way to go! - thanks everyone for your answers.