One of the following sentences is nonsensical. Which one is it?
Options:
- Sentence A: "Cars can run on rails."
- Sentence B: "Trains can run on rails."
 Let's be accurate as possible. So think first.

Show your work and conclude with the exact phrasing "Therefore, the final answer is [answer]." where [answer] is just the final number or expression that solves the problem.
user
Cars are designed to be driven on roads.
The final answer: Sentence A.