Synthesis of DNA over RNA template occurs in `:`

Options

A. TMV
B. Reovirus
C. `T_(2)` bacteriophage
D. Rous sarcoma virus

Explanation

**Step-by-Step Solution:**

1. **Understanding the Question**: The question asks where the synthesis of DNA occurs over an RNA template. This process is known as reverse transcription.

2. **Identifying Key Concepts**: Reverse transcription is a process where RNA serves as a template to synthesize DNA. This is the opposite of the usual transcription process where DNA is used to synthesize RNA.

3. **Recognizing Retroviruses**: Retroviruses are a class of viruses that possess RNA as their genetic material and have the ability to perform reverse transcription. One well-known retrovirus is the Rous sarcoma virus.

4. **Evaluating the Options**: The question provides four options, and we need to determine which one is associated with the synthesis of DNA from an RNA template:
- Option A: Rous sarcoma virus (correct)
- Option B: TM virus (incorrect)
- Option C: Reovirus (incorrect)
- Option D: T2 bacteriophage (incorrect)

5. **Conclusion**: The correct answer is the Rous sarcoma virus, as it is a retrovirus capable of reverse transcription, synthesizing DNA from an RNA template.

**Final Answer**: The synthesis of DNA over an RNA template occurs in the Rous sarcoma virus.

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