Please submit your concern

Explanation:

Option 1 can be easily ruled out, as the author says, “not because of the lack of suitable telescopes, but rather the lack of suitable things at which to point at.”
Option 3 is also ruled out as that is not the reason for the difficulty. The author further says, “Because these events took place over 13 billion years ago, if astronomers are to have any hope of unravelling them they must study objects that are at least 13 billion light years away.” That points to option 2, which indicates that the events are extremely old.
Option 4 comes close as the author further discusses quasars and mentions the difficulty in locating and studying them, as they are far off. But in light of the information given- that the event is a very old one- option 2 is more appropriate.
Hence, the correct answer is option 2.