Rejection of a transplanted organ is due to the activity of

Options

A. B cells
B. Neutrophilis
C. T cells
D. Eosinophils

Answer

### Step-by-Step Solution:

1. **Understanding Transplantation**:
- Transplantation refers to the process of transferring cells, tissues, or organs from one individual to another. This is often done to replace a malfunctioning organ in a recipient.

2. **Immune Response to Transplantation**:
- When an organ is transplanted, the recipient's immune system recognizes the new organ as foreign. The immune response consists of two main types: cellular and humoral (or antibody-mediated).

3. **Cellular Response**:
- The cellular immune response primarily involves T cells, a type of lymphocyte. These T cells play a crucial role in identifying and attacking the transplanted organ.

4. **Stages of Rejection**:
- The rejection of a transplanted organ occurs in two stages:
- **Sensitization Stage**: The immune system recognizes the transplanted tissue as foreign.
- **Effector Stage**: The immune system mounts a response to destroy the foreign tissue.

5. **Identifying the Key Players**:
- Among the various components of the immune system, T cells are the main players in the rejection of transplanted organs. Other cells like B cells, neutrophils, and eosinophils also play roles in the immune response but are not primarily responsible for organ rejection.

6. **Conclusion**:
- Therefore, the rejection of a transplanted organ is primarily due to the activity of T cells.

### Final Answer:
The rejection of a transplanted organ is due to the activity of **T cells**.

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