Rubber is

Options

A. Monoterpene
B. Diterpene
C. Tetraterpene
D. Polyterpene.

Answer

To answer the question "Rubber is:", we need to analyze the classification of terpenes and how rubber fits into that classification.

### Step-by-Step Solution:

1. **Understanding Rubber**:
- Rubber is a natural polymer primarily made up of isoprene units.

2. **Identifying Isoprene**:
- Isoprene has the chemical formula C5H8.

3. **Defining Terpenes**:
- Terpenes are classified based on the number of isoprene units they contain:
- **Monoterpenes**: 2 isoprene units (C10H16)
- **Diterpenes**: 4 isoprene units (C20H32)
- **Tetraterpenes**: 8 isoprene units (C40H64)
- **Polyterpenes**: More than 8 isoprene units, meaning it can have a variable number of isoprene units.

4. **Classifying Rubber**:
- Since rubber is a polymer made up of many isoprene units, it falls under the category of polyterpenes because it consists of a large number of isoprene units.

5. **Conclusion**:
- Therefore, the correct classification of rubber is that it is a **polyterpene**.

### Final Answer:
Rubber is a **polyterpene**.

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