Hi there!
The answer you are looking for is option C. A pause or hesitation.
<em>A comma can be used to give direction either to a reader or a speaker to where to take a pause,</em><em> </em>and also to make the sentence most effective and convincing. In other words, a comma can be used near the end of a sentence to separate contrasted coordinate elements or to indicate a distinct pause or shift.
Answer:
I would go with A but I'm not sure
I think it is B but A would be a good choice
