(c) : The elements of group 14 show an oxidation state of +4 and +2. The compounds showing an oxidation state of +4 are covalent compound and have tetrahedral structures. e.g. SnCl4, PbCl4, SiCl4, etc. whereas those which show +2 oxidation state are ionic in nature and behave as reducing agent.
e.g. SnCl2, PbCl2 , etc. Further as we move down the group, the tendency of the element to form covalent compound decreases but the tendency to form ionic compound increases.