I believe the answer is B
The (main) function of the "network media" is the "<span> to transmit signals from device to device" because by doing this and allowing this to happen, this the signals would also send messages, and by this, it would then also be known as social media, and by this, it would be able to send pictures, text, and etc. This would be the point of the "network media".</span>
Literally just do a colon and parenthesis :(
:( :-(
