23. Manny has three ways to travel the 8 kilometres from home to work: driving his car takes 12 minutes, riding his bike takes 24 minutes and walking takes 1 hour and 44 minutes. He wants to know how to get to work as quickly as possible in the event that he is riding his bike and gets a flat tyre. He has three strategies: (i) If he is close to home, walk back home and then drive his car. (ii) If he is close to work, just walk the rest of the way. (iii) For some intermediate distances, spend 20 minutes fixing the tyre and then continue riding his bike. He knows there are two locations along the route to work where the strategy should change. How far apart are they? (A) 2km (B) 3km (C) 4km (D) 5km (E) 6 km