Suppose you are writing software for a radio station that manages its playlists. the program will generate candidate playlists from a record library automatically and station personnel can then check and modify them. disc jockeys must also be able to change playlists when they are used because what is actually played is often different from what is planned. the playlists are then used to generate reports for paying royalties. you must decide what sort of data structure to use to store playlists. make a choice and write a design rationale. your rationale should explain the factors that went into your decision, the design alternatives you considered, your evaluation of design decisions, and the reasoning for your final choice.