Which source gives the highest fidelity?

Suppose I have four new, identical TVs, all capable of 1080i resolution. All are the same model and are calibrated equally (brightness, contrast, color temp, etc.). All are tuned to the same 1080i program (e.g., the evening news on CBS-HD in New York City).

Set A gets its input from a rooftop antenna. Set B gets its input from a copper cable company. Set C from a fiber-optic cable/phone company. Set D from a satellite. In all cases there are NO intervening components between the wall outlet and the sets except the set top boxes for Sets B, C and D. Assume that signal strengths are strong enough to prevent pixelation and the most appropriate cables are used.

Which source should best picture? Would differences be noticeable, even to a somewhat casual viewer?

I'm assuming that Set A delivers the truest picture because there is no intervening cable/satellite company circuitry - regardless of how high the quality of the each component in the signal chain might be - to degrade the signal.

Thanks for you inputs.

R1
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