It is even confusing to me. The trains are on separate tracks but the question implies that they will crash into each other. Which could happen even if they are on separate tracks (very low chance but non-zero given there is a malfunction).
Now even if they are on the same track it doesn't mean they would crash into each other as they still could brake in time.
Now even if they are on the same track it doesn't mean they would crash into each other as they still could brake in time.