It could be a mix of fatigue, due to it being your last section.

@atlaspoocd But thats an assumption we have no information on. We'd have to assume that Veronica made a legitimate offer to Sal for this reasoning to hold water. And this is not a question about assumptions, but what must be true, given all the information presented.

@SoniaKulkarni Think about it like this.

We know that it takes 500 million years for a Quasar's light to reach Earth.

However, the author also claims that a Quasar cannot burn for more than 100 million years.

Thus, by the time the light reaches Earth, the light of the Quasar must have burnt out 400 million years ago.

Making E, "No quasar that has ever been seen from Earth exists any longer.', must be true.

500 million - 100 million = 400 million