Final answer:
The sympathetic nervous system causes Option 1: Pupil dilation. This occurs when norepinephrine binds to receptors in the iris muscle, adapting the body for 'fight or flight' scenarios by allowing more light into the eye.
Thus option 1: Pupil dilation. is correct answer.
Step-by-step explanation:
The sympathetic nervous system is part of the autonomic nervous system that prepares the body for 'fight or flight' situations. When activated during stressful events, it has several effects on the body, such as pupil dilation (mydriasis), inhibition of salivation, increased heart rate, and bronchial dilation.
These responses are facilitated by the neurotransmitter norepinephrine, which binds to adrenergic receptors causing these physiological changes.
Regarding the options presented in the student's question, the sympathetic nervous system specifically causes Option 1: Pupil dilation. Mydriasis occurs when norepinephrine binds to an adrenergic receptor in the iris' radial muscle fibers, allowing more light to enter the eye and enhancing visual acuity.
Thus option 1: Pupil dilation. is correct answer.