Falling Mortality and Fertility Rates Have Altered the Kinship Bonds

Falling mortality and fertility rates have altered the kinship bonds of people in the United States. The major change has been

A) an increase in horizontal ties and a decrease in vertical ties across generations.
B) decline in bonds of kinship of all types.
C) decreasing vertical links across generations.
D) decreasing horizontal bonds and increasing vertical bonds of kinship across generations.