To solve this question, the user needs to have knowledge about the OSI model and the functions of the presentation layer.

The presentation layer is the sixth layer of the OSI model, responsible for the formatting and presentation of data. It translates data from the application layer into a format that can be transmitted over the network.

Now, let's go through each option and determine which of them operate at the presentation layer:

A. MIDI: MIDI is a protocol used for communication between musical devices. It operates at the application layer, not the presentation layer.

B. FTP: FTP is a protocol used for file transfer between systems. It operates at the application layer, not the presentation layer.

C. SMTP: SMTP is a protocol used for sending email messages between servers. It operates at the application layer, not the presentation layer.

D. TFTP: TFTP is a protocol used for simple file transfers between systems. It operates at the transport layer, not the presentation layer.

E. JPEG: JPEG is a file format used for storing and transmitting digital images. It operates at the presentation layer, as it involves the formatting and presentation of data.

Therefore, the answer is: D. A and E