Malcolm is studying alone in his room late at night when he hears a loud noise downstairs. his heartbeat increases significantly and his breathing becomes shallow. he wonders if a burglar has entered the house and decides to investigate. when he gets downstairs he discovers his cat has knocked over a plant stand. his body begins to relax and return to normal. which part of his nervous system is responsible for returning malcolm to a normal state?
a. spinal cord
b. somatic nervous system
c. sympathetic nervous system
d. parasympathetic nervous system
e. the corpus callosum

The answer is d,

The vagus nerve carries parasympathetic impulses to most chest and abdominal organs, including the lungs, heart and digestive organs.

white blood cells or wbc s are mainly 2 types-

1.agranulocytes

2.granulocytes

the monocytes or macrophages of agranulocytes , dendritic cells which are accessory leucocytes, and b cells which is one type of lymphocytes   identify the antigens present on the pathogen's surface. these three cells are called antigen presenting cells(apc) which are phagocytes and destroy the antigens by secreting antitoxins. besides this leukocyte is always plays vital role in the immunity of the body.

i think that d. wind is the answer.   i missed the question when i answered a. currents.