Answer: D Equilateral
Explanation: Center of a triangle is a point where lines intersect. There 4 most popular: centroid, circumcenter, orthocenter and incenter.
Altitude or Height of a triangle is a perpendicular line is draw from a vertex to the opposite side. There are 3 heights and they united (or intersect) at a point called Orthocenter
Incenter is a point where the three angle bisectors meet. Angle bisector is a line that divide the angles of the triangle in two equal angles.
Generally, each center is positioned at a different location on the triangle (in one example, the point is located outside the triangle).
However, there is a case in which incenter and orthocenter are coincidental. That case is for a equilateral triangle, a triangle whose angles and sides are the same.