Which of These Definitions of Species Most Closely Fits the Biological

Multiple Choice

Which of these definitions of species most closely fits the biological species concept?

A) For asexually reproducing organisms, members of the same species are based on DNA and RNA base sequence analysis.
B) Members of the same species look almost exactly alike.
C) Members of the same species are all morphologically similar.
D) Members of the same species can mate and produce fertile offspring.