Detailed Instructions: In this task, you're given a four sentences of story written in natural language. Your job is to complete end part of the story by predicting appropriate last sentence which is coherent with the given sentences.
Q: Sentence1: Derek loved exploring caves. Sentence2: He had been to most of the famous caverns in North America. Sentence3: He particularly liked caves with gemstones in the walls. Sentence4: Derek became a park ranger at a cave system.
A:
Derek developed an interest in mountains after his long time in caves.