greater shielding power of s-electrons of gallium atom.

poor shielding power of s-electrons of gallium.

poor shielding power of $d$-electrons of gallium.

greater shielding power of $d$-electrons of gallium.

A-III, B-IV, C-I, D-II

A-II, B-III, C-IV, D-I

A-IV, B-I, C-II, D-III

A-IV, B-III, C-I, D-II

$\mathrm{Sn}<\mathrm{Cd}<\mathrm{Zr}<\mathrm{Sr}$

$\mathrm{Sn}<\mathrm{Sr}<\mathrm{Cd}<\mathrm{Zr}$

$\mathrm{Cd}<\mathrm{Zr}<\mathrm{Sr}<\mathrm{Sn}$

$\mathrm{Zr}<\mathrm{Sr}<\mathrm{Cd}<\mathrm{Sn}$

carbon $>$ nitrogen $>$ oxygen $>$ fluorine

oxygen $>$ carbon $>$ nitrogen $>$ fluorine

fluorine $>$ nitrogen $>$ carbon $>$ oxygen

oxygen $>$ fluorine $>$ nitrogen $>$ carbon