A radio galaxy is shown they are emitted by the supermassive black hole at the center of the galaxy. Therefore , they are emitted by the supermassive black hole at the center of the galaxy is correct .
Radio galaxies are a type of galaxy that emits strong radio waves. These radio waves are produced by jets of relativistic particles that are ejected from the galaxy's central black hole.
The jets travel for thousands of light-years before they collide with the intergalactic medium, producing the radio emission that we observe.
The other answer choices are incorrect. The two giant lobes on opposite sides of the galaxy are the visible manifestations of the jets, but they do not emit radio waves themselves.
The brightest stars in the galaxy do not emit enough radio waves to account for the observed emission.
And the bright nucleus at the center of the galaxy does emit radio waves, but these radio waves are not produced by the black hole.