Anuclear family consists of a. kinship groups, which are very tightly bound together. b. all close blood relatives who live together. c. any group of people related by common ancestry. d. a husband-wife pair and their dependent children. e. a husband-wife pair their children and in-laws.

The answer is letter d. a husband and wife pair, together with their dependent children. Nuclear Family also known as elementary family, in sociology and anthropology. A Nuclear family is a cluster of individuals who are unified by bonds of trust and parenthood or guardianship and made up of of a pair of grown-ups and their communally acknowledged kids.

i think it is the third one.