The correct option is A Zinjanthropus
The first human fossil probably belonged to Zinjanthropus. It is an extinct hominin postulated from a skull found in Olduvai Gorge, Tanzania, in 1959 and originally designated Zinjanthropus boisei by Louis S.B. Leakey. It was later renamed Paranthropus boisei. It lived in Eastern Africa during the Pleistocene epoch from about 2.3 until about 1.2 million years ago. The brain had a small capacity of 500-550cc. Hence option A is correct.