The correct option is A Increasing cranial capacity
From the early primates to modern man, there were many important evolutionary changes. However, the most significant among them was the remarkable increase in the cranial capacity (brain capacity) of 1300 - 1600 cubic centimeters. This change highlighted the benefits of two of our greatest tools - adaptability and social cohesion. Brain power improved with diets of meat and seafood. The cooking of meat meant that less efforts would be spent on digestion. These resulted in superior brain power, enabling modern man to dominate planet Earth.