Alist of two choices that follows in a sequence for identification is a:
a: dichotomous key
b: classification schema.

Classification schema.

Explanation:

A classification of scheme is the product of arranging things into the group of classes. Classification scheme is related to the Carolus Linnaeus, who is the father of taxonomy and gives the system of classification. Arrange in the increasing order : Species, genus, family, order, class, phylum, kingdom.

The benefits of the classification scheme are : Classification facilitates the identification of the organisms, helps to study the evolutionary  relationships of the organisms, and helps to maintaining the relationships among the group of organisms.      

An identification key is also known as taxonomic key, which is useful to identifying unknown person.