Innate immunity includes all of the following except:

• A. Skin as a physical barrier
• B. Production of antibodies by B cells
• C. Phagocytosis by macrophages
• D. Inflammatory response

Answer: (B)

Verified step by step guidance

1. Step 1: Begin by understanding the concept of innate immunity. Innate immunity is the body's first line of defense against pathogens and is non-specific, meaning it does not target specific pathogens. It includes physical barriers, cellular responses, and chemical defenses.
2. Step 2: Review the components of innate immunity. These include physical barriers like the skin, cellular responses such as phagocytosis by macrophages, and processes like the inflammatory response. These mechanisms act quickly and are present from birth.
3. Step 3: Contrast innate immunity with adaptive immunity. Adaptive immunity is specific and involves the production of antibodies by B cells, which target specific antigens. This process requires prior exposure to the pathogen and is not part of innate immunity.
4. Step 4: Analyze the options provided in the question. Identify which mechanisms are part of innate immunity (e.g., skin as a physical barrier, phagocytosis by macrophages, inflammatory response) and which are part of adaptive immunity (e.g., production of antibodies by B cells).
5. Step 5: Conclude that the correct answer is the production of antibodies by B cells, as this is a function of adaptive immunity, not innate immunity.