The correct answer is A: The receiver is unable to reject strong signals outside the AM or FM band. A broadcast AM or FM radio receiving an amateur radio transmission unintentionally is caused by fundamental overload - the receiver cannot reject strong signals outside its intended band. When a strong amateur signal (even on a different frequency) is near the broadcast receiver, it can overload the receiver's front-end, causing it to receive the signal even though it's outside the AM or FM band. This is a receiver problem, not a transmitter problem. For amateur radio operators, understanding this helps when neighbors report interference - the issue is often their receiver's lack of filtering, not your transmitter's output.