The answer is lateralization of brain function. This is the predisposition for some neural functions or cognitive processes to be more prevailing in one hemisphere than the other. The medial longitudinal fissure divides the human brain into two separate cerebral hemispheres, connected by the corpus callosum.
The answer to the question is option C
Are you talking about the benthic zone?
It is a reduction of number of cells of their parent cell in half equal numbers.