What column to merge on?

Chicago provides a list of taxicab owners and vehicles licensed to operate within the city, for public safety. Your goal is to merge two tables together. One table is called taxi_owners, with info about the taxi cab company owners, and one is called taxi_veh, with info about each taxi cab vehicle. Both the taxi_owners and taxi_veh tables have been loaded for you to explore.

Choose the column you would use to merge the two tables on using the .merge() method.