Answer: (B ) The word "But" should not be capitalized.
Explanation:
The irony is that the "nice" mom---Laurie's mom---is the one with the badly-behaved son. She just doesn't realize at first that Charles and Laurie are the same person. Again, the irony is that she believes only a bad mother would have such a bad kid, but HER own son turns out to be the bad kid.
the answer is D, comforting
My answer to this question would be A.