Final answer:
Option 4). Non-African humans have interbred with Neanderthals, evidenced by 1-4% Neanderthal DNA in European and Middle Eastern populations; Denisovans also interbred with Neanderthals and early modern humans, with direct evidence from the hybrid individual Denisova 11.
Step-by-step explanation:
There is evidence of limited past interbreeding with Neanderthals in all non-African humans today. The DNA of modern populations in Europe and the Middle East shows evidence of this interbreeding; these populations contain anywhere from 1 to 4 percent Neanderthal DNA. It has been established by scientific investigations into nuclear and mitochondrial DNA that Neanderthals and Denisovans interbred with early modern humans and had a common ancestor. More evidence for these historical interbreeding events comes from discoveries like the identification of Denisovan DNA in some contemporary populations, including Melanesians and Tibetans.
A first-generation hybrid known as Denisova 11, or "Denny," who had one Denisovan parent and one Neanderthal parent, was one particularly noteworthy find. Direct evidence of interbreeding between these two extinct hominin groups can be found in this individual. Although the two main groups known to have interbred with our direct ancestors are the Neanderthals and the Denisovans, current research indicates that there might have been other "ghost populations" that added to the genetic composition of modern humans.