9 is related to 16 following a certain logic. Following the same logic, 25 is related to 36. To which of the following is 81 related using the same logic?

Let's analyze the pairs of numbers given:
9 is related to 16:

9=3
2

The next consecutive integer is 4, and 4
2
=16.

25 is related to 36:

25=5
2

The next consecutive integer is 6, and 6
2
=36.

Following the exact same logic for 81:

81=9
2

The next consecutive integer is 10, and 10
2
=100.