Answer:
b.)

Explanation:
To find if a set of lengths makes a right triangle, use the Pythagorean theorem:

If a and b squared equal c squared, then the set makes a right triangle. C (the hypotenuse) is the largest number of the set because the hypotenuse is always the largest side in a right triangle.
Use the options:
a.) insert values:

260 does not equal 289, so a is wrong.
b.) insert values:

2,500 equals 2,500, so b is correct.
Finito.