What Did Rosenberg and Trevathan Discover in Their Study Comparing

What did Rosenberg and Trevathan discover in their study comparing human and nonhuman primate birth?

A) They are remarkably similar despite the large difference in brain size.
B) The infant nonhuman primate's head is oriented in the opposite direction of the human infant's head,the former facing backwards.
C) The infant nonhuman primate's head is oriented sideways in comparison to the human infant's head.
D) Primates have a much lower success rate than humans;nonhuman primate infants often do not survive the birth process.