Question

In addition to the immune system, we are protected from disease by

• A. The skin
• B. Mucous membranes
• C. Natural secretions such as acids, protein-digesting enzymes, and antibiotics
• D. All of the above

Answer 1

The correct option is D All of the above

Natural barriers and the immune system defend the body against organisms that can cause infection. Natural barriers include the skin, mucous membranes, tears, earwax, mucus, and stomach acid. Also, the normal flow of urine washes out microorganisms that enter the urinary tract. These are the barriers to infection.

So, the correct answer is 'All of the above'.