Context: There was a bit of up and down riding , but it went through shady woods , mostly , and made for a very pleasant ride . After the woods we ran into a fairly steep hill , and the gravel road became more rough , so we decided to walk the bikes up the hill , hoping that the next little town was just on the other side . When we crested the hill , we saw that there was another , even steeper hill , so even though we may have been less than a mile from the town , we decided to turn back , after riding a little over 10 miles .
Question: Why did they have to walk the bikes ?
Option 0: The gravel got difficult to navigate .
Option 1: The wood path became rough .
Option 2: None of the above choices .
Option 3: The hill had mud all over it .
Answer: 0