Final answer:
The accurate statement regarding hominins that left Africa around 1.8 million years ago is that they were ancestors of modern humans. They were likely Homo erectus, not Australopithecus, and they did not colonize the Americas at that time.
Step-by-step explanation:
The statement(s) that is/are accurate regarding hominins that first left Africa around 1.8 million years ago are as follows:
(B) they were the ancestors of modern day humans
The earliest hominins, including those classified under Homo genera and particularly Homo erectus, migrated out of Africa and settled parts of Europe and Asia. These migrations were the basis for the populations that would eventually evolve into modern humans. However, they did not immediately colonize the entire globe, including the Americas, or belong to the genus Australopithecus; the latter had become extinct by that time. The colonization of the Americas occurred much later, with the last major settlements taking place around 12,000 - 15,000 years ago via the Bering Land Bridge. Statement (B) is thus the most accurate of the options provided, as these early hominins are indeed ancestral to modern humans.