Answer:
Answer D is correct.
Explanation:
By inspection, the side lengths are {3, 4, 5}, and this triplet satisfies the Pythagorean Theorem: 3^2 + 4^2 = 5^2. Thus this IS a right triangle.
One could also find the lengths of the three sides using the distance formula and the endpoints of each line segment forming the triangle.
Answer D is correct.