Which human-like primates existed $15$ million years ago?

The fossil man who made cave paintings is:

......... hunted with stone weapons.

Which of the following sequences is correct for the evolutionary history of humans?

$A$: 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.

The cranial capacity of modern man is