The largest amount (90%) of cellulose amongst the natural materials is present in
(a) Wood
(b) Cotton fibers
(c) Rayon
(d) Roughage

Options

A. Wood
B. Cotton fibers
C. Rayon
D. Roughage

Answer

To determine which natural material contains the largest amount of cellulose (90%), we need to analyze the options provided:

1. **Wood**: Wood does contain cellulose, but it is not composed entirely of cellulose. It typically contains cellulose, hemicellulose, and lignin, with cellulose making up a smaller percentage than 90%.

2. **Cotton fibers**: Cotton is known for being a natural fiber that is primarily composed of cellulose. In fact, cotton fibers can contain more than 90% cellulose, making it one of the purest forms of natural cellulose.

3. **Rayon**: Rayon is a semi-synthetic fiber made from regenerated cellulose. While it is derived from cellulose, it does not contain the same high percentage of cellulose as cotton fibers.

4. **Roughage**: Roughage refers to dietary fiber, which includes various plant materials. While it does contain cellulose, it is a mixture of different types of fibers and does not have a cellulose content as high as that found in cotton.

Based on this analysis, the correct answer is **(b) Cotton fibers**, as it contains the largest amount of cellulose (around 90%) among the options provided.

### Step-by-Step Solution:
1. **Identify the options**: Look at the four options provided: Wood, Cotton fibers, Rayon, and Roughage.
2. **Analyze each option**:
- Wood: Contains cellulose but not 90%.
- Cotton fibers: Contains more than 90% cellulose.
- Rayon: Derived from cellulose but not as high as cotton.
- Roughage: Contains cellulose but is a mix of fibers.
3. **Determine the option with the highest cellulose content**: Cotton fibers are identified as having the highest cellulose content.
4. **Conclude the answer**: The correct answer is (b) Cotton fibers.