Answer:
C. a conference call
Step-by-step explanation:
Conference call is used for conversation either within or outside a team in an organization. It connects people in different location together .
Much cost is not expended on conference call unlike physical meetings which might involve travelling longer distance.
One of the disadvantages of conference call is that conversation might not be fully rich due to the numbers of participants unlike one on one phone conversation.
Other means of having conversation within or outside an organization are through emails, text, social networking and video conferencing.