Final answer:
B. A blended family is one where at least one partner has children from a previous marriage. It is distinct from a nuclear family, which is a two-parent household with biological children, and from an extended family, which includes additional relatives.
Step-by-step explanation:
A blended family is a family in which at least one partner has children from a previous marriage, living in the home or nearby. Unlike a nuclear family, which consists of a two-parent household with their biological children, a blended family merges two separate family units into a new, integrated social entity. This type of family structure is increasingly common in societies where serial monogamy is prevalent, such as the United States. In 2009, Pew Research estimated that about 16 percent of all American children lived in blended families. Blended families contrast with extended families, which may include not just parents and their children but also other relatives such as grandparents, aunts, uncles, and cousins.