Why does a dichotomous key offer two choices at each stage and not more than two?

A dichotomous key is a device that can be used to easily identify an unknown organism. The Word dichotomous comes from two Greek Words that together mean, "divided in two parts". A dichotomous key consists of a series of two part statements that describe characteristic of organisms. At each step of a dichotomous key the user is presented with two choices. As the user makes a choice about a particular characteristic of an organism they are led to a new branch of the key. Eventually the user will be led to the name of the organism that they are trying to identify.

di=2