Etymology is to word as lineage is to what?

Etymology refers to the study of the origin of words and how their meanings and forms have evolved over time. Similarly, lineage pertains to the line of descent from an ancestor. In this analogy, just as etymology reveals the historical background and ancestral connections of a word, lineage reveals the historical connections and ancestral descent in a family or species.

Choosing the term "descendant" is appropriate because it explicitly refers to those who are descended from a particular ancestor, mirroring how etymology relates to the origin of a word. This connection highlights the direct relationship between an ancestor and their descendants. The other options, while related in different contexts, do not parallel the direct relationship central to both etymology and lineage. For example, description refers to explaining characteristics but lacks the ancestral tie, while letter and formation don’t pertain directly to descendant relationships.