Three rings with radius R and mass m are connected in a triangle as shown in the figure. The center of mass is at the centroid of an equilateral triangle connecting the centers of the rings (this triangle must have side length 2R). The (2D) mass moment of inertia about the center of mass of the assembly is O IGz = 6mR? O IGzz = 3mR? O IGzz = 7mR? O An answer not listed O IGzz = 7mR /3