Distance between the focussing parts of the two human eyes is
about.

Options

A. 2 cm
B. 4 cm
C. 7 cm
D. 10 cm.

Answer

To find the distance between the focusing parts of the two human eyes, we can follow these steps:

### Step-by-Step Solution:

1. **Understanding the Question**: The question asks for the distance between the focusing parts of the two human eyes, which is essentially the distance between the pupils of the eyes when focusing on an object.

2. **Defining Accommodation Power**: The accommodation power of the human eye refers to the range within which the eye can focus on objects. This range is typically from a minimum distance to an infinite distance.

3. **Identifying the Minimum Distance**: The minimum distance at which the human eye can focus is approximately 7 cm. This means that the eye can clearly see objects that are at least 7 cm away.

4. **Evaluating the Options**: The given options are 2 cm, 4 cm, 7 cm, and 10 cm. Since we know that the minimum focusing distance is 7 cm, we can evaluate the options:
- 2 cm: Incorrect, as it is less than the minimum focusing distance.
- 4 cm: Incorrect, as it is also less than the minimum focusing distance.
- 7 cm: Correct, as it matches the minimum focusing distance.
- 10 cm: Incorrect, as it exceeds the minimum focusing distance but is not the distance between the eyes.

5. **Conclusion**: Based on the evaluation, the correct answer is 7 cm, which is the distance between the focusing parts of the two human eyes.

### Final Answer:
The distance between the focusing parts of the two human eyes is about **7 cm**.