Task: Question Generation
Input (English): Background Paragraph: About 10% of sedimentary rocks are limestones. The solubility of limestone in water and weak acid solutions leads to karst landscapes, in which water erodes the limestone over thousands to millions of years. Most cave systems are through limestone bedrock. 
Story: Bob has been planning a trip with some friends, and they have mentioned that they want to see limestone. Bob also has a retreat for work that is being planned, and his boss has stated that he doesn't want to travel to a place with high amounts of limestone, as he finds it boring. Bob's travel agent has supplied him with two options for vacation, Mt. Pike, and Meramec Caverns.
Output (English): Where should Bob take his friends?