The correct option is C muscle--protection from pathogens
Muscle will not give protection from pathogens. The main function of the muscular system is movement.
Endothelium is a type of epithelium that lines the interior surface of blood capillaries.
Adipose tissue, or fat, is an anatomical term for loose connective tissue composed of adipocytes. Its main role is to store energy in the form of fat, although it also cushions and insulates the body. The cells in nervous tissue that generate and conduct impulses are called neurons or nerve cells.