Martha invites John to come to lunch. Martha knows that her private road

Martha invites John to come to lunch. Martha knows that her private road is dangerous to travel, having been heavily eroded by recent rains. She doesn’t warn John of the condition, reasonably believing that he will notice the deep ruts and exercise sufficient care. John’s attention, while driving over, is diverted from the road by the screaming of his child, who has been stung by a bee. He fails to notice the condition of the road, hits a rut, and skids into a tree. If John is not contributorily negligent, is Martha liable to John? Explain.