Triangle ABC has vertices A(-6, 6), B(4, 2), and C(-4, 0).
Which statement about triangle ABC is true?
A. Since none of the sides are congruent, it is not a right triangle.
B. Since none of the sides have slopes that are negative reciprocals, it is not a right triangle.
C. Since two of the sides have slopes that are negative reciprocals, it is a right triangle.
D. Since two of the sides are congruent, it is a right triangle.