1 mL of " $x$ volume" $\mathrm{H}_2 \mathrm{O}_2$ solution on heating gives 20 mL of oxygen gas at STP. The $(\mathrm{w} / \mathrm{v}) \%$ corresponding to " x volume" of $\mathrm{H}_2 \mathrm{O}_2$ is

• A

  $3.03$
• Correct answer
  B

  $6.06$
• C

  $9.09$
• D

  $30.3$

Hence, the correct answer is option: 'B'.