An individual transitions from a brightly lit outdoor courtyard into a dark, unlit corridor. This change in light intensity is detected by photoreceptors in the retina, initiating a reflex arc that alters the size of the pupil as shown in the diagram.
Which row correctly describes the response of the iris muscles and the division of the autonomic nervous system activated to adapt to this dark environment?
Circular muscles: contract; Radial muscles: relax; Sympathetic nervous system\text{Circular muscles: contract; Radial muscles: relax; Sympathetic nervous system}Circular muscles: contract; Radial muscles: relax; Sympathetic nervous system
Circular muscles: relax; Radial muscles: contract; Sympathetic nervous system\text{Circular muscles: relax; Radial muscles: contract; Sympathetic nervous system}Circular muscles: relax; Radial muscles: contract; Sympathetic nervous system
Circular muscles: contract; Radial muscles: relax; Parasympathetic nervous system\text{Circular muscles: contract; Radial muscles: relax; Parasympathetic nervous system}Circular muscles: contract; Radial muscles: relax; Parasympathetic nervous system
Circular muscles: relax; Radial muscles: contract; Parasympathetic nervous system\text{Circular muscles: relax; Radial muscles: contract; Parasympathetic nervous system}Circular muscles: relax; Radial muscles: contract; Parasympathetic nervous system