Australopithecines probably lived in the

The modern man differs from the apes in:

$A$: The brain reaches between $75$ and $80$ percent of its adult size within the first two years,and its full size at the age of $6$ years.
$R$: From an evolutionary point of view,the human gestation period is believed to be shortening.

Neanderthal man lived in

The cranial capacity of the brain is represented by which of the following?

What was the brain capacity of $Homo$ $erectus$?