RNA is the genetic material in

Options

A. prokaryotes
B. eukaryotes
C. Tobacco Mosaic Virus (TMV)
D. E.coli.

Explanation

**Step-by-Step Solution:**

1. **Understanding Genetic Material**: Genetic material is the substance that carries genetic information from one generation to the next. It can be either DNA (deoxyribonucleic acid) or RNA (ribonucleic acid).

2. **Types of Organisms**:
- **Prokaryotes**: These are primitive organisms that lack a well-defined nucleus. Their genetic material is typically double-stranded DNA, and examples include bacteria like archaebacteria.
- **Eukaryotes**: These are more advanced organisms that possess a true nucleus with a nuclear membrane. They also have double-stranded DNA as their genetic material. Examples include protists, fungi, plants, and animals.

3. **Identifying RNA as Genetic Material**: The question specifically asks where RNA serves as the genetic material.
- The Tobacco Mosaic Virus (TMV) is a notable example of a virus that has RNA as its genetic material. TMV is a positive-sense single-stranded RNA virus that infects plants, particularly tobacco.

4. **Evaluating the Options**:
- **Option 1 (Prokaryotes)**: Incorrect, as prokaryotes primarily have DNA as their genetic material.
- **Option 2 (Eukaryotes)**: Incorrect, as eukaryotes also primarily have DNA as their genetic material.
- **Option 3 (TMV)**: Correct, since TMV is a virus that has RNA as its genetic material.
- **Option 4 (E. coli)**: Incorrect, as E. coli is a bacterium that has DNA as its genetic material.

5. **Conclusion**: Based on the analysis, the correct answer to the question "RNA is the genetic material in" is **TMV**.