The Family System Has Changed in the United States Over

The family system has changed in the United States over the last few decades. In particular, child rearing, which was once the sole province of the mother, is now being shared with fathers, other relatives, day care centers, school systems, babysitters, and an endless list of surrogates who assume responsibility for this important task. This social change, which helps to maintain society's stability, is known as

A) the equilibrium model.
B) the conflict model.
C) multilinear evolutionary change.
D) unilinear evolutionary change.