Which one of the following molecules cannot serve as a monomer for an addition polymer?

Here cannot serve as a monomer for an addition polymer as in addition polymerisation, the monomers are unsaturated compounds and commonly derivatives of ethene. Rest other are monomers for addition polymers. For e.g., $\mathrm{C}\mathrm{l}\mathrm{C}\mathrm{H}=\mathrm{C}{\mathrm{H}}_2$ (monomer of PVC)