Which of the following keystrokes or characters is sent as part of ARQ communications to request a direct TELEX call to a shore-based location?

Correct Answer: Option D — DIRTLX023123456+

The command 'DIRTLX' followed by the full destination number and a plus sign is the standard format for requesting a direct telex connection. This command is processed by the coast station's automated equipment to route the call to the specific shore-based subscriber.