Which is most likely an effect of the evolution of a larger brain in humans

Brain can process and store lot of information. Large brains means large heads, which makes childbirth more difficult and painful for human mothers.

Explanation:

A larger brain provides better performance. human brain size increases rapidly.  Human brains are larger, more complex brains which enabled humans of this time period to interact with each other and with their surroundings in different ways.

The prefrontal cortex is slightly a larger part in the human brain. Humans have the largest cerebral cortex. It is a sheet of brain cells that folds itself multiple times in order to fit inside the skull. It enables us to process everything we see and hear and think.