How many cocoons of the silkmoth Bombyx mori have to be boiled for one pound of silk?

Options

A. (a) 2500
B. (b) 100
C. (c) 1000
D. (d) 2000

Answer

To determine how many cocoons of the silkmoth Bombyx mori need to be boiled to produce one pound of silk, we can follow these steps:

### Step-by-Step Solution:

1. **Understand the Source of Silk**:
- The silk is produced from the cocoons of the silkmoth Bombyx mori. Each cocoon contains thread-like structures that are spun into silk.

2. **Length and Diameter of Silk**:
- Each cocoon produces raw silk that can be approximately 300 to 900 meters long with a diameter of about 10 microns.

3. **Silk Production Requirement**:
- To produce silk fabric, a significant number of cocoons are required.

4. **Conversion of Weight**:
- One pound of silk is approximately equivalent to 0.4 kg.

5. **Cocoon Requirement Calculation**:
- It is estimated that to produce one pound (0.4 kg) of silk, about 2000 to 3000 cocoons are boiled.

6. **Choosing the Nearest Value**:
- Given the options provided (A: 2500, B: 100, C: 1000, D: 2000), the nearest figure to the estimated requirement is 2500.

7. **Final Answer**:
- Therefore, the answer is **2500 cocoons**.