Answer:   A & C

The side lengths of A could be used to create a right triangle. 

Using the Pythagorean Theorem, 3² + 4² = 5² or 9 + 16 = 25. 

The side lengths of B could not be used to create a right triangle. 

Using the Pythagorean Theorem, 6² + 7² is not equal to 10² or 36 + 49 ≠ 100.

The side lengths of C could be used to create a right triangle. 

Using the Pythagorean Theorem, 5² + 12² = 13² or 25 + 144 = 169.