Which component of the blood is part of the body’s immune system? a. plasma b. platelets c. red blood cells d. white blood cells

White blood cell

The lymphatic system is an important part of the immune system. The lymph nodes filter lymph fluid as it flows through them, trapping bacteria, viruses, and other foreign substances, which are then destroyed by special white blood cells called lymphocytes.

White blood cells (also called leukocytes or leucocytes and abbreviated as WBCs) are the cells of the immune system that are involved in protecting the body against both infectious disease and foreign invaders.

c. heat from the poles back down towards the equator.