Although all the answers do take affect in the article but it is asking for main idea and mainly the selection is talking about irony so i would go with A
Answer:
I think it would be lighthearted
Explanation:
None of the other answers really make sense, but if you are allowed a second answer if it is not lighthearted it would probably be serious
I believe the correct is the third option. It is important to preview sources before using them in your research because it reveals deeper concepts. Reading deeply the sources would allow you to have a deeper understanding of the sources and determine which parts of the sources are useful to your research.
The Answer should be B. Credentials as going by it's definition and all.