Answer: Immune system
Step-by-step explanation:
The immune system is a set of structures and biological processes that protect the body against diseases. In order to function properly, the immune system must detect an immense variety of agents, from viruses to parasites, and distinguish them from healthy body tissue.It protects the body from infections through stratified defense mechanisms with progressive specificity. The physical barriers (like skin, membranes) prevent pathogens from entering.