Selec the wrong statement :

Options

A. Mosaic disease in tobacco and AIDS in human being are caused by viruses.
B. The viroids were discovered by D.J. Ivanowski.
C. W.M. Stanley showed that viruses could be crystalized.
D. The term ' contagium vivum fluidum ' was coined by M. W. Beijerinek.

Answer

To solve the question, we need to identify the wrong statement among the given options (A, B, C, D). Let’s analyze each statement step by step.

### Step-by-Step Solution:

1. **Analyze Statement A**:
- Statement A claims that "The Mozak disease in tobacco and AIDS in human beings are caused by viruses."
- **Verification**:
- The mosaic disease in tobacco is caused by the Tobacco Mosaic Virus (TMV).
- AIDS is caused by the Human Immunodeficiency Virus (HIV).
- **Conclusion**: This statement is correct.

2. **Analyze Statement B**:
- Statement B states that "Viroids were discovered by G. J. Ivanovsky."
- **Verification**:
- Viroids were actually discovered by Theodor Otto Diener in 1971.
- G. J. Ivanovsky is known for his work on viruses, not viroids.
- **Conclusion**: This statement is incorrect.

3. **Analyze Statement C**:
- Statement C claims that "W. M. Stanley showed that viruses could be crystallized."
- **Verification**:
- W. M. Stanley is indeed known for demonstrating that viruses could be crystallized.
- **Conclusion**: This statement is correct.

4. **Analyze Statement D**:
- Statement D states that "M. W. Beijerinck coined the term contagium vivum fluidum."
- **Verification**:
- M. W. Beijerinck is credited with coining the term "contagium vivum fluidum" to describe infectious agents that could pass through filters that retained bacteria.
- **Conclusion**: This statement is correct.

### Final Conclusion:
- The only incorrect statement among the options is **Statement B**, which incorrectly attributes the discovery of viroids to G. J. Ivanovsky instead of Theodor Otto Diener.

### Answer:
**The wrong statement is B: "Viroids were discovered by G. J. Ivanovsky."**