____________ a thermoplastic, is used as a packaging material for food products and liquids such as milk.

Options

A. Bakelite
B. Polyester
C. Polystyrene
D. Polythene

Explanation

**Step-by-Step Text Solution:**

1. **Identify the Type of Material:** The question asks for a thermoplastic used in packaging materials for food products and liquids. Thermoplastics are a type of plastic that becomes moldable upon heating and solidifies upon cooling.

2. **Consider Common Thermoplastics:** Some common thermoplastics include polyethylene (polythene), polypropylene, and polyvinyl chloride (PVC). Among these, we need to find one that is specifically used for food packaging.

3. **Focus on Food Packaging:** Polythene is widely known for its use in food packaging due to its flexibility, durability, and resistance to moisture. It is commonly used for items like plastic bags, containers, and wraps.

4. **Identify the Monomer:** The monomer for polythene is ethylene, which has the chemical formula CH2=CH2. When ethylene undergoes polymerization, it forms polythene.

5. **Conclude the Answer:** Based on the information gathered, the answer to the question is "Polythene."

**Final Answer:** Polythene, a thermoplastic, is used as a packaging material for food products and liquids such as milk.

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