X takes 2 hours more than Y to walk d km, but if X doubles his speed, then he can make it in 1 hours less than Y. How much time does Y require for walking d km?

1. $$3$$ hours
2. $$4$$ hours
3. $$\frac{d}{2}$$ hours
4. $$\frac{2d}{3}$$ hours

A

1

B

2

C

3

D

4