Which legal relationship best describes a lineal descendant?

A lineal descendant refers to a person who is in a direct line of descent from another individual. This includes children, grandchildren, and so forth, indicating a straight lineage down the generational line. "Direct descendant" effectively captures this relationship, as it specifies that the individual is directly descended from another person rather than related through collateral lines, such as siblings or cousins.

In contrast, the other options describe different familial relationships. For instance, a direct ancestor refers to those from whom one descends, such as parents or grandparents, which is not the same as being a descendant. Collateral relatives are those who share a common ancestor but are not in a direct line, such as aunts, uncles, or cousins. Co-heirs refers to individuals who inherit from the same deceased individual but does not specifically address the lineage aspect that "direct descendant" conveys. Thus, the answer accurately captures the concept of a lineal descendant by emphasizing the direct nature of the relationship.