The correct answer is C. A scalene triangle can be a right triangle.
This is because a scalene triangle is a triangle where all of the sides and angles are different from one another. This automatically tells us that options A and D are incorrect, because equiangular triangles have all 3 angles equivalent and if two sides were of equal length in the triangle, then it would not be scalene.
This leaves us with options B and C. An obtuse triangle simply has one angle with a measure greater than 90 degrees, and a right triangle is a triangle with a right angle (an angle that measures exactly 90 degrees). Scalene triangles can be both obtuse and right, as long as the side lengths and angles are not equal to one another. This makes option B incorrect, and option C the only correct option out of the four.
