Correct option is B
Given:
Initial radius = 10 cm
Final radius = 50 cm
Initial distance between two dots = 25 units
Let the new distance between the two dots be x units.
Solution:
The key to solving this problem is understanding uniform scaling on a sphere.
If the balloon expands uniformly, then all distances on the surface (arc lengths, distances between points) scale proportionally with the radius.
Final Answer: (b) 125