What should you do if something in a neighbor’s home is causing harmful interference to your amateur station?
Work with your neighbor to identify the offending device
Politely inform your neighbor that FCC rules prohibit the use of devices that cause interference
Make sure your station meets the standards of good amateur practice
All these choices are correct✓Bonne réponse
Explication
All three actions belong in the response: cooperating with the neighbor to identify the offending device is the only way to locate it, unlicensed devices must not cause harmful interference to a licensed service, and confirming your own station is clean rules out your equipment as a contributor. None of them excludes the others.