The correct option is C If assertion is true but reason is false.
Alpha taxonomy is also known as classical taxonomy and parent branch of other taxonomical studies. This is the very initial phase of taxonomic activity which involves identification, naming, and characterization of biological species based on their morphology.
Omega taxonomy involves identification, naming, and characterization of biological species, which is based on all the information or data available including morphology. It has widest scope.
Therefore, assertion is true but reason is false.