Solution:
For a triangle, an incenter can be obtained by drawing the angle bisectors of the triangle and locating the point of intersection of these bisectors. Remember that the incenter of a triangle is a triangle center. Now, the angle bisector of a triangle is a line segment that bisects one of the vertex angles of a triangle and ends up on the corresponding opposite side. The three angle bisectors of a triangle meet in a single point, called the incenter.
According to this, the correct answer is:
D.