The correct answer is A: Block the amateur signal with a filter at the antenna input of the affected receiver. Fundamental overload of a non-amateur radio or TV receiver by an amateur signal can be reduced or eliminated by blocking the amateur signal with a filter at the antenna input of the affected receiver. This is the correct approach because the problem is the receiver's inability to reject strong out-of-band signals. A filter (typically a band-pass filter for the desired service or a notch filter for the interfering frequency) blocks the amateur signal before it enters the receiver. For amateur radio operators, this is the proper solution - the interference is caused by receiver overload, so the filter goes on the affected receiver, not the transmitter.