Roger is part of a team that is responsible for employing a new information system, the design of which was developed using customary structured methods. to manage the intricacy of the application development process, roger wants to deploy structured development techniques, and he asks pete, his coworker, for information about these techniques. pete tells him about structure charts, which show program modules and the relationships among them using various graphical symbols. pete informs roger that one type of element in a structure chart is a data couple, which shows data that one module passes to another. what symbol is used for a data couple?