Correct answer: 7–8 cm
Explanation:
The least distance of distinct vision is the minimum distance at which an object can be seen clearly without strain.
- For a normal adult, this distance is about 25 cm.
- However, children below the age of 10 generally have more flexible eye lenses, allowing them to focus on objects at a closer range.
Therefore, the least distance of distinct vision for such children is typically around 7–8 cm.
Hence, the correct answer is: 7–8 cm.