The correct answer is C. Audio response unit.
An audio response unit is a device that produces spoken output from a computer. It is used to provide information to users in a clear and concise way. Audio response units are often used in applications such as telephone banking, automated answering systems, and voice-activated assistants.
Audit trail is a record of all transactions that have occurred in a system. It is used to track changes to data and to identify any unauthorized activity. Card punch is a device that converts data from punched cards into machine-readable form. Magnetic tape is a storage medium that uses magnetic fields to store data.
None of the above options are devices that transmit messages in verbal form.