The percentage of ionization of 1 L of $x \mathrm{M}$ acetic acid is 4.242 and is called solution "A". The percentage of ionization of 1 L of $y \mathrm{M}$ acetic acid is 3 and is called solution "B". Solution "A" is mixed with solution "B". What is the concentration of acetic acid in the resultant solution? $\left(\mathrm{K}_{\mathrm{a}} \text { of acetic acid }=1.8 \times 10^{-5}\right)$

• A

  0.05 M
• Correct answer
  B

  0.015 M
• C

  0.02 M
• D

  0.15 M

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