Q: What type of barrier physically blocks pathogens from entering the body?


Read this paragraph and choose the correct option from the provided answers:

Mechanical barriers physically block pathogens from entering the body. The skin is the most important mechanical barrier. In fact, it is the single most important defense the body has. The outer layer of the skin is tough and very difficult for pathogens to penetrate.

 Choices:

- Solid

- potential

- molecular

- mechanical


A:
mechanical