Which of the following best describes a blended family?

A blended family is best described as a family formed when single parents marry each other, often bringing children from previous relationships into the new family structure. This definition captures the essence of a blended family, which typically consists of both the biological and stepparents, along with their respective children, creating a new family unit that incorporates various dynamics and relationships.

The other options do not accurately represent a blended family. A family with only one parent refers to a single-parent family, which does not involve the merging of two families. A family that includes grandparents and grandchildren describes a multigenerational family setup, which is different from the blended family concept. Lastly, a family without any children signifies a childless family, which again does not align with the definition of a blended family where children from prior relationships are present. Thus, the most precise characterization of a blended family is the one that involves the merging of single-parent families through marriage.