The correct option is B Annulus
Numerous pores through which the nucleus communicates with the cytoplasm interrupt the nuclear envelope. The nuclear pore is guarded by two annuli, an outer and an inner annulus, each with eight globular subunits 15-20 nm diameter, projecting inwards from them are eight radially arranged spokes. In the center of the pore there is a central granule or plug. Such structure is called nuclear pore complex.