Choose the incorrect statement from given below:

Options

A. (1)The cell mediated immune response is responsible for graft rejection
B. (2) Metastasis is the most feared property of malignant tumour
C. (3) Cocain and L.S.D. causes depression
D. (4) T-cell do not form antibody hut help B-cell produce them

Answer

To solve the question of identifying the incorrect statement from the given options, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Question**: The question asks us to choose the incorrect statement from a list of statements related to biology, specifically focusing on immunology and tumor biology.

2. **Analyze Each Statement**:
- **Statement 1**: "Cell mediated immune response is responsible for the graft rejection."
- This statement is true. The cell-mediated immune response, primarily involving T lymphocytes, does play a crucial role in recognizing and rejecting grafts (non-self tissues).

- **Statement 2**: "Metastasis is the most feared property of the malignant tumor."
- This statement is also true. Metastasis refers to the spread of cancer cells from the primary site to other parts of the body, which is indeed a significant concern in cancer treatment.

- **Statement 3**: "Cocaine and LSD cause depression."
- This statement is incorrect. Cocaine and LSD are classified as stimulants, not depressants. Cocaine is a natural stimulant, and LSD is a synthetic stimulant. Therefore, this statement is false.

- **Statement 4**: "T cells do not form antibodies but help the B cells to produce them."
- This statement is true. T cells assist B cells in the immune response but do not produce antibodies themselves.

3. **Identify the Incorrect Statement**: From the analysis, Statement 3 is the only incorrect statement.

4. **Conclusion**: The incorrect statement is "Cocaine and LSD cause depression."

### Final Answer:
The incorrect statement is: **"Cocaine and LSD cause depression."**

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