Context: The plan was that H , V and I were going to stick together and ride it at a casual speed . We did just that , rolling along the trails at a good speed , overtaking people from time to time on the uphills and going moderately on the downhills . The trails were great . Not too difficult , but not too easy .

Question: What were they using to ride the trail ?
Options:
0. A bicycle .
1. Roller blades .
2. A scooter .
3. A skateboard .
Answer: 0