Answer: D. {10, 24, 26}
Explanation
We plug each triple into the Pythagorean theorem.
Let's try choice A.
a^2 + b^2 = c^2
11^2 + 59^2 = 61^2
121 + 3481 = 3721
3602 = 3721
The last equation is false, so choice A is not a right triangle.
Similar situations happen with choices B and C.
We cross choices A, B, and C off the list.
Choice D on the other hand is a right triangle because of this scratch work shown here.
a^2 + b^2 = c^2
10^2 + 24^2 = 26^2
100 + 576 = 676
676 = 676
We arrive at a true statement, so the first equation is true when (a,b,c) = (10,24,26). This is one of the infinitely many Pythagorean triples. It is based on the Pythagorean triple (5,12,13). Double each value of (5,12,13) to end up with (10,24,26).