Substances which can be elastically stretched to large value of strain are called

Options

A. Isomers
B. Isodiapheres
C. Plastomers
D. Elastomers

Explanation

To solve the question, we need to identify the correct term for substances that can be elastically stretched to a large value of strain. Let's break down the options provided:

1. **Isomers**: These are compounds that have the same molecular formula but different structural arrangements. This term does not relate to elasticity.

2. **Isodiapers**: This term is not commonly used in the context of materials science or elasticity. It does not fit the description.

3. **Plastomers**: These are materials that exhibit both plastic and elastic properties, but they are not primarily known for being elastically stretched to large strains.

4. **Elastomers**: These are polymers that can undergo significant elastic deformation when stretched. They can return to their original shape after the deforming force is removed, making them suitable for applications where large strains are involved.

Based on the definitions and characteristics of the substances, the correct answer is:

**Elastomers**.

### Step-by-Step Solution:
1. **Identify the question**: The question asks for substances that can be elastically stretched to large values of strain.

2. **Analyze the options**: Review each option to determine its relevance to elasticity and strain.

3. **Eliminate irrelevant options**:
- Isomers do not relate to elasticity.
- Isodiapers are not relevant.
- Plastomers have some elastic properties but are not primarily known for large elastic strains.

4. **Select the correct option**: Elastomers are known for their ability to be elastically stretched to large strains while returning to their original shape.

5. **Conclude the answer**: The correct answer is **Elastomers**.