What Is the Role of White Blood Cells in Protecting

What is the role of white blood cells in protecting the body from invading organisms?​

A) Phagocytes release antibodies against the invaders into the bloodstream.
B) T-cells release a chemical trail for identification of invaders.
C) ​B-cells engulf and digest the foreign particles.
D) Killer T-cells seek out and destroy all foreign particles with the same identity.
E) ​Skin cells are a type of white blood cell that provide a physical,protective barrier.