The correct answer to this open question is the following.
Although there are no options attached we can say the following.
The significance of archaeological discoveries in East Africa to our understanding of its prehistory is that "archeologists have found artifacts that help historians correct a false understanding of East Africa’s history."
In recent years, scientists and archeologists have made some important discoveries that changed the original perception of the evolution of humans that started in that region of Africa.
Human fossils have been dated as far as 200,000 years ago. We are talking about H*mo Sapiens fossils.
The earliest fossilized human remains have been found in Eastern Africa.
Ethiopia is the place in Eastern Africa where the earliest fossilized human was found. Anthropologists have named the skeleton "Lucy," a 3.2 million years ape. Lucy was an Australopithecus afarensis early human. It was discovered by Donald C. Johanson, in 1974, close to Hadar, Ethiopia.