We can say that a letter that begins with <em>I </em><em>need </em><em>your </em><em>help </em><em>ASAP </em>is informal because it is personal and direct.
We know that beacuse the sentence has been written to a trusted recipient and it uses abbreviations (ASAP).
It would be pop culture because it is refering to Superman.
I think the dependent clause is C
-Be respectful
-Be aware of strong language and all caps
-Cite your sources
-Use Grammar and spelling does mater
Hope this helped
