Obstacle to large scale transplantation of organs is

Options

A. Insufficiency of organ donors
B. Immunological rejection of foreign bodies
C. Religious or ethnic considerations
D. Lack of effective surgical techniques

Answer

### Step-by-Step Solution:

1. **Understanding Organ Transplantation**:
- Organ transplantation is a medical procedure where an organ is removed from one body (the donor) and placed into another body (the recipient) to replace a damaged or missing organ.

2. **Identifying the Main Challenge**:
- One of the significant challenges in organ transplantation is the body's immune response. The immune system is designed to recognize and attack foreign substances that enter the body.

3. **Immune Response Mechanism**:
- When a transplanted organ is introduced into the recipient's body, the immune system identifies it as a foreign entity. This triggers an immune response, where the body produces T-cells and antibodies to attack the transplanted organ.

4. **Consequences of Immune Response**:
- The immune response can lead to the rejection of the transplanted organ, as the T-cells and antibodies can damage the organ, impairing its function and potentially leading to organ failure.

5. **Conclusion**:
- Therefore, the primary obstacle to large-scale organ transplantation is the immunological rejection of foreign bodies, which is a result of the immune system's response to the transplanted organ.

### Final Answer:
The obstacle to large-scale transplantation of organs is the immunological rejection of foreign bodies.

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