Answer: 2) a research study published on a university’s website about how being in a zoo affects animals.
The most credible source on his list is option 2. With option 1, Roberto would only have access to subjective opinions, which are not a good source of evidence for research. Option 3 is an advertisement, which means that it does not contain a lot of information. It also means that it is likely to present zoos as a very desirable thing. Finally, option 4 is also likely to be subjective and biased, as the author is a zoo employee. On the other hand, option 2 comes from a research study published on a university's website, which means it is likely to be trustworthy.
Without reading the text, you can use context clues in the question. Only questions A and B mention her general time in school. We can rule out B, because rather than a main Idea, it shows a detail, leaving us with A as the most reasonable answer
