Which Choice Is Considered to Be a Fundamental Problem with Application

Which choice is considered to be a fundamental problem with application of the phenetic species concept?

A) The phenetic species concept uses phenotypic traits to create clusters; therefore, it cannot be applied to bacterial and unicellular species.
B) The phenetic species concept only looks at whether reproduction occurs between populations; therefore, it cannot be applied to asexually reproducing species.
C) The phenetic species concept weighs all traits equally, which can lead to ambiguous cluster boundaries when defining species.
D) The phenetic species concept uses phenotypic traits to create clusters, but phenotypic traits can be similar due to convergent evolution rather than common ancestry.