Hint:Chemotaxonomy is a classification system that involves the identification of organisms based on the similarities and differences in their biochemical properties. It is also called chemosystematics. The biological classification of plants and animals is done purely relying upon their biochemical composition.
Complete answer:Chemistry plays a major role in the coexistence of various organisms that live in an ecosystem. Taxonomy is a branch of classifying and naming living organisms based on their specific characters. Chemotaxonomy focuses on the identification of organisms based on their chemical or biochemical properties. Proteins, amino acids, peptides, nucleic acids are the chemical compounds that are being studied in chemotaxonomy.
There are four major groups of compounds that form the basis of chemotaxonomical classification. These are phenolics, alkaloids, non-protein amino acids, and terpenoids. When these chemicals are obtained from plants they are termed phytochemicals.
The plants utilize some chemical compounds for their metabolic processes. These chemicals are called primary metabolites. The chemicals that perform non-essential functions or are used in defense or protection are called secondary metabolites. Generally, it is the secondary metabolites that comprise phytochemicals. These are used in various human activities.
Thus, from the above discussion, we can conclude that the use of phytochemical data in systematic botany comes under the branch of chemotaxonomy. Systems botany is an approach towards using some information and techniques and then incorporating them under a single umbrella of knowledge.
So, option B is correct.
Note: The advancement in analytical techniques has led to the rise of chemotaxonomy. Various chemical analysis tests can even detect the traces of a chemical compound. The chemotaxonomy approach improves the existing plant differentiation system.