گزینه «1» $x=\frac{{{\left[ S{{O}_{3}} \right]}^{2}}}{{{\left[ S{{O}_{2}} \right]}^ {2}}\left[ {{O}_{2}} \right]}=\frac{{{\left( 3/0 \right)}^{2}}}{{{\left( 1/0 \right)}^{2}}\left( 2/0 \right)}=4/5\Rightarrow x\ne k$ 

گزینه «2» $x=\frac{{{\left[ S{{O}_{3}} \right]}^{2}}}{{{\left[ S{{O}_{2}} \right]}^{2}}\left[ {{O}_{2}} \right]}=\frac{{{\left( 5/0 \right)}^{2}}}{{{\left( 2/0 \right)}^{2}}\left( 2/5 \right)}=2/5\Rightarrow x\ne k$ 

گزینه «3» $x=\frac{{{\left[ S{{O}_{3}} \right]}^{2}}}{{{\left[ S{{O}_{2}} \right]}^{2}}\left[ {{O}_{2}} \right]}=\frac{{{\left( 0/6 \right)}^{2}}}{{{\left( 1/0 \right)}^{2}}\left( 0/1 \right)}=3/6\Rightarrow x=k$

گزینه «4» $x=\frac{{{\left[ S{{O}_{3}} \right]}^{2}}}{{{\left[ S{{O}_{2}} \right]}^{2}}\left[ {{O}_{2}} \right]}=\frac{{{\left( 1/5 \right)}^{2}}}{{{\left( 0/5 \right)}^{2}}\left( 1/0 \right)}=9\Rightarrow x\ne k$