Kemija - 2012./13. jesen - 35.

A. ${\mathrm{S}}_2{\mathrm{O}}_5{}^{2-}\backslash mathrm\{S\}\_\{2\}\; \backslash mathrm\{O\}\_\{5\}\{\}^\{2-\}$

B. ${\mathrm{S}\mathrm{O}}_4{}^{2-}\backslash mathrm\{SO\}\_\{4\}\{\; \}^\{2-\}$

C. ${\mathrm{S}\mathrm{O}}_3{}^{2-}\backslash mathrm\{SO\}\_\{3\}\{\; \}^\{2-\}$

D. ${\mathrm{S}}_2{\mathrm{O}}_3{}^{2-}\backslash mathrm\{S\}\_\{2\}\; \backslash mathrm\{O\}\_\{3\}\{\; \}^\{2-\}$