The given figure is We know that convex polyhedron is one in which the line segment connecting on the surface of a polyhedron totally sits within or on the polyhedron. Otherwise, it is a concave polyhedron. In the given figure, let us consider two points A & B. Join the points AB. We get a line segment AB. The line AB is not totally contained within or on the polyhedron. So, it is a concave polyhedron The correct option is (2).