Which statement best describes the difference between the sympathetic and parasympathetic nervous systems?

a.
the sympathetic system sends signals within the brain and the parasympathetic system sends signals between the brain and the body.
b.
the sympathetic system contains the brain and spinal cord and the parasympathetic system contains the peripheral nerves.
c.
the sympathetic system controls voluntary body movements and the parasympathetic system controls involuntary functions.
d.
the sympathetic system prepares the body for stress and activity and the parasympathetic system prepares the body for rest.

D. The sympathetic system prepares the body for stress and activity and the parasympathetic system prepares the body for rest.

Explanation:

parasites can detrimentally affect their host, but also must not allow their host to die before they can complete their life cycle. some parasites have complex life cycles with many different hosts, and have had to find ways of persisting in many different environments during the change from one host to another. ectoparasites live outside the body of the host, and can more easily  disperse, but are  more exposed to predators, parasites, parasitoids. endoparasites live inside the body of the host, and are therefore protected from the outside environment. but they can be  attacked by the host's immune system. they have therefore developed  mechanisms for dispersal such as  complex life cycles.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.