In which of the following polymers ethylene gylcol is one of the monomer units?

Options

A.
B.
C.
D.

Explanation

To determine which polymer has ethylene glycol as one of its monomer units, we can follow these steps:

### Step-by-Step Solution:

1. **Identify Ethylene Glycol**:
- Ethylene glycol is a diol with the chemical formula \( C_2H_6O_2 \) or structurally represented as \( HO-CH_2-CH_2-OH \).
- It consists of two hydroxyl (-OH) groups attached to a two-carbon chain.

2. **Understand Polymerization**:
- Polymers are formed by the process of polymerization, where monomer units join together through chemical reactions.
- In the case of ethylene glycol, it can undergo condensation polymerization with certain acids.

3. **Identify Potential Polymers**:
- One well-known polymer that uses ethylene glycol as a monomer is **Terylene** (also known as PET - Polyethylene Terephthalate).
- Terylene is formed by the polymerization of ethylene glycol and terephthalic acid.

4. **Chemical Reaction**:
- The reaction involves the hydroxyl groups of ethylene glycol reacting with the carboxylic acid groups of terephthalic acid.
- During this reaction, water is eliminated, leading to the formation of ester linkages, resulting in the polymer structure.

5. **Conclusion**:
- Therefore, the polymer that has ethylene glycol as one of its monomer units is **Terylene**.

### Final Answer:
**Terylene** is the polymer in which ethylene glycol is one of the monomer units.