1. For each of the following scenarios choose the "best" data structure from the following list or a combination of data structures: an unsorted array, linked list, DLL, circular LL, stack, queue. In each case, justify your answer briefly. a. Suppose that a grocery store decided that customers who come first will be served first b. A list must be maintained so that any element can be accessed randomly c. A program needs to remember operations it performed in opposite order d. The size of a file is unknown. The entries need to be entered as they come in. Entries must be deleted when they are no longer needed. It is important that structure has flexible memory management e. A list must be maintained so that elements can be added to the beginning or end in O(1)