On the basis of source, polymers can be classified as

Options

A. natural
B. synthetic
C. semi-synthetic
D. All of these

Answer

To classify polymers based on their source, we can follow these steps:

### Step 1: Understand the Classification of Polymers
Polymers can be classified based on their source into three main categories: natural, synthetic, and semi-synthetic.

### Step 2: Define Natural Polymers
Natural polymers are those that are found in nature. They are not manufactured or altered by humans. Examples of natural polymers include:
- Starch
- Proteins
- Nucleic acids (like DNA and RNA)

### Step 3: Define Synthetic Polymers
Synthetic polymers are man-made polymers that are created through chemical processes. They do not occur naturally and are produced in laboratories or industrial settings. Examples of synthetic polymers include:
- Polyvinyl chloride (PVC)
- Nylon

### Step 4: Define Semi-Synthetic Polymers
Semi-synthetic polymers are derived from natural polymers but have been chemically modified to enhance their properties or to create new materials. They are not completely natural nor entirely synthetic. An example of a semi-synthetic polymer is:
- Cellulose acetate (used in rayon)

### Step 5: Conclude the Classification
Based on the definitions and examples provided, we can conclude that polymers can be classified into three categories based on their source:
1. Natural Polymers
2. Synthetic Polymers
3. Semi-Synthetic Polymers

Thus, the correct answer to the question is that polymers can be classified as all of these types.