It is definitely not true that many small rural communities have best transport, so we can reject the option b) and d) together with it.
The best answer is that they don't have mass transit systems (a is the correct answer). It's not true that they can walk everywhere because they can for example be forced to walk to a different town if they need a hospital.
1) it effect them by how high up they are in the mountains.
so i could answer the second one for you but hope what i gave you helps :)
