91Ó°ÊÓ

A phylogenetic tree is a hierarchical or visual representation of the relationships between species and their forefathers. A taxon is a taxonomic unit that symbolizes an individual or a group of individuals.

Option (a) is referred to as a sister taxon. Sister taxa are a group of taxa that descended from the same parent or diverged at the same time. As a result, option is the proper response (a).

Option (b) is referred to as a base taxon. The term "basal taxon" refers to a taxon that does not branch out into any additional daughter taxa. Option (b) is thus erroneous.

Option (c) is represented by a rooted tree. A rooted tree is one in which all taxa descended from a single ancestor, and there is no such thing as rooted taxa. Option (c) is thus erroneous.

Option (d) is presented as a pair of dichotomous taxa. Dichotomous growth is characterized by the division of each taxon, group, or branch into two offspring taxa, groups, or branches. It is not used to refer to the offspring of the same parent taxon. Option (d) is thus erroneous.

Sister taxa are those that have a common ancestor or diverged from the same location.