Hello there! :D
Firstly, I want to say that some of the written out answers look incomplete. I am going to try my best to answer this question and give you context so that you can choose the best answer choice! :)
There are two main systems within the boundaries our nervous system:
The CNS (central nervous system) and the PNS (peripheral nervous system).
Struturally,
the CNS constistues the brain and spinal chord,
the PNS consistutes your nerves and ganglion.
Functionally, the CNS recieves messages from the PNS and sends messages to the PNS. Think of the CNS as the control center, and the PNS as the reactor.
The PNS has two systems within it, the somatic nervous system, and the autonomic nervous system. The somatic nervous system senses things consciously percieved (ie. eye sight, pain, taste) and the autonomic nervous system senses things unconsciously percieved and controled (ie. stress, anxiety, etc). The point being, you cannot control when it happens or stop the function of it consciously.
The autonomic nervous system holds two main systems, which would be the parasympathetic system and the sympathetic system. The parasympathetic system helps maintain your circadian rythmn, replenish energy, and relax your body. The sympathetic system is known as your "fight or flight" system. This system can be triggered by test anxiety, unsafe situations, and in any case where your life or emotional well being is being threatened.
My best answer for this question, in my opinion, would be the autonomic nervous system, and the sympathetic system. The sympathetic system deals with fear (fight or flight) and is controlled by the autonomic nervous system).
I hope this helps you and you have a wonderful day,
Kai xx
