Correct Answer - D
`S_(2)O_(6)^(2-)` (Dithionate ion)
`.^(Theta)O-underset(O)underset(||)overset(O)overset(||)S-underset(O)underset(||)overset(O)overset(||)S-O^(Theta)`
(b) `S_(4) O_(6)^(2-)` (Tetrathionate ion)
`^ThetaO-underset(O)underset(||)overset(O)overset(||)S-underset(O)underset(||)overset(O)overset(||)S-O^(Theta)`
(c ) `S_(2) O_(3)^(2-)` (Thiouslphate ion)
`.^(Theta)O-underset(O)underset(||)overset(O)overset(||)S-O^(Theta)`
(d) `S_(2) O_(7)^(2-)` (Pyrosulphate ion)
`^(Theta)O-underset(O)underset(||)overset(O)overset(||)S-underset(O)underset(||)overset(O)overset(||)S-O^(Theta)`
In (d) there is no `S -S` bond .
