In Their Study of 24,000 People Living in Germany, Lucas

In their study of 24,000 people living in Germany, Lucas, Clark, et al. (Focus on Research: Are we still happy after the honeymoon?) found in their analysis of individual variations in responses to marriage that

A) most of the initial gains in happiness were soon lost.
B) nearly everyone benefited from marriage.
C) about half were happier and half unhappier consistent with the idea of hedonic leveling where pre-marriage happiness determines how much a person benefits from marriage.
D) most couples were initially happier, but about half became disillusioned over time, consistent with the idea that romantic/passionate love "cools off."