The immune system<span> is made up of a network of cells, tissues, and organs that work together to protect the body. One of the important cells involved are white blood cells, also called leukocytes, which come in two basic types that combine to seek out and destroy disease-causing organisms or substances.</span>
The answers could be vasodilation and vasoconstriction (respectively) if that’s what u are studying.
Option C would be correct. The organ system can plays many parts at one time. Also, it is the only system listed.
Hope this helps!
