According to the multiregional model for human origins,
A. Homo sapiens arose in Africa and in Asia at about the same time from ancestral populations of H. neanderthalensis.
B. populations of Homo erectus in different regions faced different selection pressures and they gave rise to races of Homo sapiens.
C. Homo sapiens evolved in Africa but then established multiregional, separately evolving populations after migrating to Europe, Asia, Australia, and North America.
D. the human evolutionary tree is really more like a bush because our ancestors evolved in many different regions and filled numerous ecological niches.