The side lengths of a triangle are 6, 8 and 12. Is this a right triangle?

A. Yes, because 6 to the 2nd power + 8 to the 2nd power < 12 to the 2nd power.
B. No, because 6 + 8 ≠ 12.
C. Yes, because 6 to the 2nd power + 8 to the 2nd power = 12 to the 2nd power.
D. No, because 6 to the 2nd power + 8 to the 2nd power ≠ 12 to the 2nd power.