Well it can't be an imperative sentence, because imperative sentences are commands, like Put away your clothes.
But it can be an exclamatory sentence, because exclamatory sentences end in exclamation points (!) and they exclaim something, like This is so fun! or Wow, you must be so tired!
So the answer is B. exclamatory. :)
Hope this helped! If you have anymore questions or don't understand, please comment on my profile or DM me. :)
