The octet rule is not obeyed in :

${\left.\mathrm{H}-\mathrm{O}=\prod _{\mathrm{C}}^0\right]}^{\mathrm{y}}-{\mathrm{O}}^{-}$ The relation between$\mathrm{x}, \mathrm{y}$ and $z$ in bicarbonate ion with respect to bond length is:

Which of the following overlaps is incorrect [assuming z-axis to be the internuclear axis] 

(a) $2{\mathrm{p}}_{\mathrm{y}}+2{\mathrm{p}}_{\mathrm{y}}\to \pi 2{\mathrm{p}}_{\mathrm{y}}$   

(b) $2{\mathrm{p}}_{\mathrm{z}}+2{\mathrm{p}}_{\mathrm{z}}\to \mathrm{\sigma } 2{\mathrm{p}}_{\mathrm{z}}$
(c) $2{\mathrm{p}}_{\mathrm{x}}+2{\mathrm{p}}_{\mathrm{x}}\to \mathrm{\pi } 2{\mathrm{p}}_{\mathrm{x}}$
(d) $1\mathrm{s}+2{\mathrm{p}}_{\mathrm{y}}\to \mathrm{\pi } (1\mathrm{s}-2\mathrm{py})$