Size of cocoon of earthworm:-

Options

A. 1 to 2 m. m
B. 2.0 to 2.4 m.m.
C. 2.0 to 2.4 c.m.
D. 5 to 8 m.m.

Answer

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the size of the cocoon of an earthworm. It's important to note the units of measurement that are typically used for such small sizes.

**Hint**: Consider what unit of measurement is appropriate for small objects like a cocoon.

2. **Identifying the Measurement Units**: Since the size of the cocoon is relatively small, it is more appropriate to measure it in millimeters rather than centimeters.

**Hint**: Think about the size of a cocoon compared to a centimeter.

3. **Recalling the Characteristics of the Cocoon**: The cocoon of an earthworm is known to be barrel-shaped and typically has a light yellow or amber color.

**Hint**: Visualize the cocoon and its characteristics to help remember its size.

4. **Determining the Size of the Cocoon**: The typical measurement of the cocoon is approximately 2 to 2.5 mm in length.

**Hint**: Focus on the specific range of measurements provided in your study materials.

5. **Evaluating the Options**: Given the options provided, we can analyze them:
- 1 to 2 mm (too small)
- 2 to 2.4 mm (correct range)
- 5 to 8 mm (too large)

**Hint**: Compare each option against the known size of the cocoon.

6. **Selecting the Correct Answer**: The correct option is 2 to 2.4 mm, as it falls within the known size range of the cocoon. The slight difference of 0.1 mm is negligible.

**Hint**: Choose the option that closely matches the known measurement.

### Final Answer:
The size of the cocoon of an earthworm is approximately **2 to 2.4 mm** in length.