________ provides a brief description of a potential problem and its possible solution

When passing a stream to a function, it must always be pass-by-__________.

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

Linda is training to become a certified network design expert and consultant.While researching about the process of cellular radio transmissions, Linda learns that when a cell phone user begins to make a call, it is picked up by the cell tower located in the cell in which the cell phone is located and that belongs to the user's wireless provider. Which of the following is the next step in this process?

A. ?The cell tower requests the cell phone user to stay in the current location until the recipient answers the call. B. ?The cell tower forwards the call to the wireless provider's Mobile Telephone Switching Office. C. ?The cell tower combines service areas into overlapping bevel-shaped zones called frames. D. ?The cell tower routes the call to the sender's telephone via his or her mobile or conventional telephone service provider.