Amit starts from a point A, walks to another point B and then returns from B to A by his car, taking a total time of 6 hours 45 minutes. If he had driven both ways in his car, he would have taken 2 hours less. How long would it take for him to walk both ways?

1. (a)7 hours 45 minutes
2. (b)8 hours 45 minutes
3. (c)8 hours 30 minutes
4. (d)8 hours 45 minutes