Applications include menu options for opening and saving files, calling on the operating system's file management routines to get the job done.

The stack peek operation

A) checks a stack to see if there are any elements in it B) removes and returns an item from the stack C) returns the item at the top of the stack, but does not remove it D) adds a single item to the stack

A context free grammar is also called a ______ grammar.

Fill in the blank(s) with the appropriate word(s).