(a) Describe the test courts use to determine cause-in-fact.
(b) Suppose that a train traveling at 35 mph collides with a car that was stalled at a crossing and injures the driver. The court determines that trains traveling faster than 25 mph are negligent, but it also determines that even if the train in question had been traveling at this slower speed, it could not have avoided hitting the car. Would the train's negligence be found cause-in-fact of the accident? Explain why or why not.