Aheterosexual couple living in the same household and raising children is defined as:

 A heterosexual couple living in the same household and raising children is defined as: Nuclear Family

Nuclear family is a term that used to describe a family with a complete pair of parents and their children.
According to statistic, nuclear family tend to do better financially compared to single-parent family and their children tend to have less criminal records.

The answer is the third one or c