Horror movies and science fiction stories are often based on the premise that one person's brain has been surgically removed and implanted in the body of another person. This would actually be impossible because a. damage to the brain is almost always fatal. b. if the corpus callosum is cut, the brain cannot function. c. the blood brain barriers would not protect against infection. d. damage to neurons in the CNS is usually considered permanent.

option D

Explanation:

In the process of surgically removing one person,s brain, there is a very high chance that a completely clean cut is not made during this procedure generating scarred nerve tissue which is the inability of nerve tissue to heal properly; scarred nerve tissue also do not transmit signals well. And these neurons do not renew themselves. They do not divide at all. Due to the fact that loss of neurons is usually permanent and the nervous system can permanently lose some of its abilities.

answer; polycythemia is the correct answer;