I think it would be the third option because it has a significant less amount of punctuation that the others?
Hello!
The correct answer would be option C. since it is describing something/someone.
Hope this helps and have a great day! :)
Answer:
Hello,
I say A, would be the answer, because someone else is saying "Open your mouth wide for the dentist." This dialogue, not a sentence because someone is saying it.
Therefore, the answer is A, Open your mouth wide for the dentist.
Hope this helps! :)
-<em>Fishylikeswater</em>