Which of the following is required when making on-the-air test transmissions?

Amateur radio regulations require that all transmissions, including brief test transmissions, be properly identified with your call sign. You cannot simply transmit a dead carrier, whistle, or test tones without announcing who is operating the radio. Distractors like restricting tests to specific nighttime hours or notifying the FCC are entirely false. The FCC does not require notification for routine testing, and you can test your equipment at any time of day, provided you do not cause intentional interference and you properly identify your station.