Which one of the following human ancestors probably lived in East African grasslands two million years ago?

Australopithecines

The correct answer is Option (3) → Australopithecines

Approximately 15 million years ago, there were primates known as Dryopithecus and Ramapithecus. These creatures were covered in hair and had a walking style similar to gorillas and chimpanzees. Ramapithecus displayed more human-like features, while Dryopithecus exhibited characteristics more apes like. Some fossils with human-like attributes have been discovered in Ethiopia and Tanzania, suggesting that around 3-4 million years ago, human-like primates existed in East Africa. These early beings were likely not taller than 4 feet but walked upright.

Around 2 million years ago, Australopithecines are believed to have inhabited East African grasslands.  They showed evidence of hunting with stone tools but primarily consumed fruit. Some of the bones among the bones discovered were different leading to the identification of the first human-like hominid called Homo habilis, with a brain capacity ranging from 650 to 800cc. They probably did not include meat in their diet.

Neanderthal man, with a brain size of about 1400cc, inhabited the Near East and central Asia between 100,000 and 40,000 years ago. They used hides for protection and practiced burial rituals for their dead.