According to Researchers in the Past Decade, What Has Been

According to researchers in the past decade, what has been an observed change in family life cycle behaviour?

A) the tendency of unmarried people becoming customers for new homes and expensive furnishings
B) the tendency of newly married people cooking at home almost every meal instead of dining out
C) the tendency of "boomerang" children returning home, sometimes with their own families
D) the tendency of parents with a second or subsequent child buying new sets of cribs, changing tables, and so forth for each child