Ais the originator of the messages expressed. a. messenger b. transmitter c. talker d. source

A "source" is the originator of the messages.

The "message source" is the total crude substance that speaks to the message. This incorporates the greater part of the "metadata" about the message (who its from and to, the subject, and so on.) also the body substance and the greater part of the connections. The full message source truly contains two particular parts — the full headers and the body.

A message is a discrete unit of correspondence proposed by the hotspot for utilization by some beneficiary or gathering of beneficiaries. A message might be conveyed by different means, including messenger, telecommunication, bearer pigeon and electronic transport.

always in school geography and mathematics.

( i don't know what exactly this means but i translated it : d )