The Systematics of Today Is Very Different from the Systematics

The systematics of today is very different from the systematics learned a generation ago. As a result, which statement is the least accurate?

A) The biological species concept has no validity.
B) The number of existing species is known with certainty.
C) The Linnaean system of classification is wrong most of the time.
D) Morphological traits are not reliable for determining species relationships.
E) Evolutionary-based classification has entirely reorganized the classification and categories of organisms and their relationships to one another.