Answer: C. The sound from the bang echoes though the universe
Explanation:
Cosmic background radiation proves the big bang because it shows that as a result of the big bang, the early universe was really hot but cooled as it expanded. Cosmic background radiation is the result of that earlier heat.
Galaxies being red-shifted means that the space between galaxies is increasing which means that the universe is expanding which provides evidence for a big bang because particles move away the single point they are concentrated in.
There was no actual bang from the big bang and sound cannot echo through space so c is incorrect.