Plasma cells are

Options

A. the same as memory cells
B. formed from the blood plasma
C. B-cells that actively secrete antibodies
D. inactive T-cells circulating in the plasma

Answer

**Step-by-Step Solution:**

1. **Understanding Plasma Cells**: Plasma cells are a type of white blood cell (WBC) that play a crucial role in the immune response. They are derived from B cells, which are a type of lymphocyte.

2. **Formation of Plasma Cells**: Plasma cells are formed when B cells are activated in response to an antigen (a foreign substance that induces an immune response). Once activated, B cells differentiate into plasma cells.

3. **Function of Plasma Cells**: The primary function of plasma cells is to secrete antibodies. Antibodies are proteins that specifically target and neutralize pathogens such as bacteria and viruses.

4. **Distinguishing Plasma Cells from Other Cells**:
- Plasma cells are not the same as mammary cells; mammary cells are involved in milk production.
- Plasma cells are not formed from blood plasma; they originate from B cells.
- Plasma cells are not inactive T cells; T cells are a different type of lymphocyte involved in cell-mediated immunity.

5. **Correct Answer**: Based on the analysis, the correct statement about plasma cells is that they are B cells that actively secrete antibodies.

**Final Answer**: Plasma cells are B cells that actively secrete antibodies.

---