The Exact Arrangement of the Ancient Hominin Phylogeny Is Unknown

The exact arrangement of the ancient hominin phylogeny is unknown, but MOST likely

A) Ardipithecus is at or near the base, and Australopithecus garhi gave rise to early Homo.
B) robust australopithecines such as Australopithecus boisei are at the base and more gracile forms such as Australopithcus africanus evolved from those early robust forms.
C) Australopithecus anamensis evolved directly into early Homo.
D) all of the different so-called species of Australopithecus are really one species, with the robust forms being males and the more gracile forms being females.