What is a valid automatic TELEX code for requesting a real-time connection to a shore-based TELEX terminal?

The answer relates to the format and procedure used when initiating a real-time connection to a shore-based TELEX terminal via an automatic TELEX system.

DIRTLX is a command that indicates the transmission of a request for real-time communication. The presence of a numerical string following DIRTLX signifies the specific TELEX number to which the connection is being requested. In option D, the format adheres to the established structure by starting with the command, followed directly by the TELEX number, and ending with a plus sign, which is required to finalize the instruction.

This structure is crucial because it ensures the correct processing of the request by the automated systems in place, allowing for a seamless connection. Each element in the command must be correctly formatted to align with international TELEX protocols, making option D the valid choice in terms of format and compliance with the procedures for establishing a TELEX connection.

Other options may fail either due to missing elements, incorrect formatting, or improper sequences, making them unsuitable for establishing the desired communication. Understanding the correct structure and phrasing is essential for effective communication through automated telecommunication systems.