Answer:
Option D, taxonomy
Step-by-step explanation:
The definition of all the terms given as option in this question is-
a) Taxon - This represents a group that signifies a rank in a given taxonomic classification
b) Taxonomist - A person who studies about the classification of organism or any thing is called a taxonomist
c) Species - It is a rank with in taxonomic classification which includes organism sharing some common traits
d) Taxonomy - it is the branch of science that deals with the classification of organisms.
Thus, Option D is correct.