Which of the following may transmit encrypted messages?
Telecommand signals to terrestrial repeaters
Telecommand signals from a space telecommand station✓Bonne réponse
Auxiliary relay links carrying repeater audio
Mesh network backbone nodes
Explication
Only a telecommand station working a space station may send codes intended to obscure the meaning of its messages, which keeps satellite control away from anyone listening. Terrestrial repeaters, auxiliary links and mesh nodes remain under the general prohibition on messages encoded to obscure meaning.