Question

all of these statements about spinal nerves are true except which one?
there are 31 pairs.
they are all mixed.
they may contain nerve fibers of both the somatic and autonomic nervous systems.
they arise directly from the brain.

Explanation:

Spinal nerves arise from the spinal cord, not directly from the brain. There are 31 pairs of spinal nerves, they are all mixed (containing both sensory and motor fibers), and they may contain nerve fibers of both the somatic and autonomic nervous systems.

Answer:

They arise directly from the brain.