Which of the following meets the FCC definition of harmful interference?

The correct answer aligns with the FCC's definition of harmful interference, which describes interference that has a serious impact on the quality of radio communication services. This includes situations where communication is significantly degraded, obstructed, or repeatedly interrupted while the service is operating according to established regulations.

Harmful interference is specifically concerned with the functional aspect of communication and its reliability. In the context of the broader framework of radio regulations, any interference that disrupts the intended operation of authorized communication represents a violation that can lead to significant consequences, both for users and service providers.

The other choices refer to varying degrees of annoyance or disruption, but do not encapsulate the severe impact defined by the FCC. For example, annoyance may not result in serious degradation of service, and static from lightning storms is a natural phenomenon that, while it can interfere, does not fit the framework of intentional harmful interference. Therefore, the emphasis on "seriously degrades, obstructs, or repeatedly interrupts" captures the essence of what constitutes harmful interference under FCC guidelines.