Which of the following describes spinal nerves?
O. They are formed from dorsal roots and ventral roots and are part of the central nervous system.
O. They are formed from elongated dorsal root and a dorsal root ganglion which merge in a distal plexus.
O. They are formed from short dorsal roots and a dorsal root ganglion.
O. They are formed from short dorsal and ventral roots, and are part of the peripheral nervous system.
O. They are formed from elongated dorsal and ventral roots which merge in a distal plexus.