Select the mismatched pair.

Options

A. W.M. Stanely-Viruses could be crystallised
B. D.J. Ivanowsky-Coined term virus
C. M.W. Beijerinck - Extract of the infected plants of tobacco cause infection in healthy plants
D. None of these

Explanation

To solve the question of selecting the mismatched pair, we can follow these steps:

### Step 1: Identify the pairs given in the question.
The pairs mentioned are:
1. W. Stanley - Related to viruses could be crystallized.
2. D.J. Ivanovsky - Coined the term virus.
3. W.M. Beijerinck - Extract of the infected plants of tobacco causes infection in healthy plants.
4. None of these.

### Step 2: Analyze each pair for accuracy.
1. **W. Stanley**: He is known for his work on the crystallization of viruses, specifically the tobacco mosaic virus. This pair is correctly matched.

2. **D.J. Ivanovsky**: He is credited with the discovery of viruses but did not coin the term "virus." This pair is mismatched because the term "virus" was actually coined by W.M. Beijerinck.

3. **W.M. Beijerinck**: He demonstrated that the sap from infected tobacco plants could infect healthy plants, which is accurate. This pair is correctly matched.

4. **None of these**: This option suggests that all pairs are correctly matched, which is not true since we found a mismatched pair.

### Step 3: Determine the mismatched pair.
From our analysis, the mismatched pair is:
- **D.J. Ivanovsky - Coined the term virus.**

### Final Answer:
The mismatched pair is **D.J. Ivanovsky - Coined the term virus.**

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