In paragraph 4, why is there an exclamation point (!) after the last sentence

A．Because the author is surprised that so many people marry in June.
B．Because the author is surprised that the marriage peak occurs in the same month as the suicides and mental hospital peak.
C．Because the author doesn't understand why the peak for suicides and marriage is the same month.
D．Because the author is excited that so many people marry in June.