**Core Concept**
Innate immunity is the first line of defense against infection and involves non-specific mechanisms that are present from birth. It provides immediate protection against invading pathogens, whereas adaptive immunity is specific and requires time to develop.

**Why the Correct Answer is Right**
Macrophages play a crucial role in innate immunity by engulfing and digesting foreign particles, bacteria, and dead cells. They also produce cytokines, which are signaling molecules that activate other immune cells, such as neutrophils and natural killer cells. Macrophages can recognize pathogens through pattern recognition receptors (PRRs), which bind to pathogen-associated molecular patterns (PAMPs), triggering an inflammatory response.

**Why Each Wrong Option is Incorrect**
**Option A:** T-cells are a type of lymphocyte involved in adaptive immunity, specifically in cell-mediated immunity. They recognize and respond to specific antigens, which is a hallmark of adaptive immunity.
**Option B:** B-cells are also involved in adaptive immunity, producing antibodies that recognize and bind to specific antigens. While B-cells play a crucial role in immunity, they are not a component of innate immunity.
**Option D:** Antibodies are proteins produced by B-cells that recognize and bind to specific antigens. Like B-cells, antibodies are a key component of adaptive immunity, not innate immunity.

**Clinical Pearl / High-Yield Fact**
Remember that innate immunity provides immediate, non-specific protection against pathogens, whereas adaptive immunity is specific and takes time to develop. Understanding the differences between these two types of immunity is crucial for developing effective treatment strategies.

**✓ Correct Answer: C. Macrophages**