A) Plane because it is a flat surface that extends in two dimensions but exists in a three-dimensional space, and also it isn't a point, a line, or an angle because a line is infinitely thin, a point is infinitesimally small, and an angle is a measurement, not a surface.
a dot on the chalkboard would represent a point, a line, ray, or line segment would be shown as lines with various symbols at either end. An angle would be shown by a combination of points and lines. In Geometry, a plane is the realm in which these graphs exist on. Therefore, by following the metaphor, the chalkboard surface would represent the plane.
