Demographic Changes Have Increased the Likelihood of Divorce in the U.S

Demographic changes have increased the likelihood of divorce in the U.S. The primary example of this is:

A) the aging of the U.S. population, that results in later age at first marriage.
B) longer life expectancy which increases the length of many marriages beyond what they would have been in the past.
C) the decreasing number of children that forces couples to focus more on each other.
D) the skewed sex ratio that gives women many more choices for potential partners.