Which of the following cells of connective tissue secrete antibodies?

Options

A. Mast cells
B. Plasma cells
C. Macrophages
D. Fibroblasts

Answer

To answer the question, "Which of the following cells of connective tissue secrete antibodies?" we will analyze each option provided:

### Step-by-Step Solution:

1. **Understanding the Question**: We need to identify which cell type in connective tissue is responsible for secreting antibodies.

2. **Reviewing the Options**:
- **Mast Cell**: These cells are involved in allergic reactions and release histamine but do not secrete antibodies.
- **Plasma Cell**: These are differentiated B lymphocytes that produce and secrete antibodies in response to antigens.
- **Macrophage**: These are immune cells that engulf and digest pathogens but do not secrete antibodies.
- **Fibroblast Cell**: These cells are responsible for producing collagen and other fibers in connective tissue but do not secrete antibodies.

3. **Identifying the Correct Cell**: From the analysis, the only cell that is known for secreting antibodies is the **Plasma Cell**.

4. **Conclusion**: Therefore, the correct answer to the question is **Plasma Cell**.

### Final Answer:
**Plasma Cell** is the cell of connective tissue that secretes antibodies.