A is incorrect: Sending raw binary data in a text message is an inefficient and generally unsupported method for delivering visual output.

B is correct: The system typically produces a downloadable file, such as a PNG image, which is then made accessible through a unique file identifier embedded in the message content, allowing the client to retrieve it.

C is incorrect: Describing complex charts using emojis is not a practical or standard method for data delivery from an agent.

D is incorrect: While emailing is possible, the direct response mechanism of agents typically involves direct communication within the application rather than external email delivery.