According to Stephen Jay Gould, What Key Fact, Ignored by Morton

According to Stephen Jay Gould, what key fact, ignored by Morton, skewered the reliability of his claims about race, skulls, and brain size?

A) Morton never defined what he meant by "black" skulls.
B) Morton never actually measured skulls.
C) Morton ignored the fact that brain size in linked to body size, and that male skulls are on average larger than female skulls.
D) Morton ignored the fact that people with more varied diets tend to have both larger bodies and skulls, and hence brains.