Answer:
<em>It affects the central nerve system.</em>
Explanation:
<u><em>It affects the biochemical and physiological functions.</em></u>
<u><em>Hope this helped! </em></u>
<u><em>-Justin</em></u>
Your brain has nerves and those nerves run throughout your system so in that case your central nervous system control everything. It is like a director it tells your heart to pump blood it signals everything it even control your homeostasis and reflex.
Well I'm not sure if I'm right but I believe that the answer is A
The cross section is the right answer