The sympathetic nervous system is the part of the autonomic system of neurons which gets activated in the condition of stress.
The stress conditions activate the sympathetic nervous system which prepares the human body for the stress condition by either fight or flight mode.
The fight or flight responses requires a large amount of energy which are produced by the activation of the parasympathetic energy therefore the sympathetic system involves the expenditure of the energy. The system is also involved in sexual arousal.
Thus, the Sympathetic nervous system is the correct answer.
