Which part of the immune system is a physical barrier?

skin
tears
mucus
stomach acid

skin is the right answer

Explanation:

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skin

Explanation:

The skin is the body's main barrier against physical insults and pathogens. This organ is an important physical barrier of the immune system.

It represents a unique environment in which immune cells interact with skin cells to maintain tissue homeostasis and induce immune responses. The skin is composed of the epidermis, dermis and a subcutaneous fatty region.

Commensal bacteria, fungi and viruses that live on the skin have beneficial effects on pathogen protection and wound healing.

The epidermis is composed of highly specialized epithelial cells known as keratinocytes. They are continually replenished in just one layer of frequently dividing basal keratinocytes.

Dead cells called cornea sites form the outermost layer and are largely responsible for the skin's barrier function.

b and c would be the answers