Which of the following one-way transmissions are permitted?
Unidentified test transmissions of less than 10 seconds in duration
Transmissions to assist with learning the International Morse code✓Bonne réponse
Regular transmissions offering equipment for sale, if intended for amateur radio use
All these choices are correct
Explication
One-way transmissions are the exception in the amateur service and the rules name the permitted kinds outright; code practice is one of them. Unidentified transmissions are never allowed, and offering equipment for sale on a regular basis runs into the pecuniary interest prohibition.