Final answer:
DNA evidence was missing during Darwin's time that would have supported the hypothesis that humans evolved in Africa from ancestral primates. This evidence later linked human genomes outside Africa closely to those of people in Africa.
Step-by-step explanation:
The evidence that was missing during Darwin's time that would have supported his hypothesis that humans evolved in Africa from ancestral primates is B) DNA evidence. While Darwin had some fossil evidence and made logical arguments in his book 'On the Origin of Species', the understanding of genetics was not developed until later. The theory that humans descended from Africa was indeed supported by subsequent research, which showed that human genomes tested outside of Africa had close ties to the genomes of people in Africa, with a genetic variance in Africa that wasn't found elsewhere. This DNA evidence, along with a more expansive fossil record, offers substantial support for the out-of-Africa theory of human evolution.