Acetone on addition to methyl magnesium bromide forms a complex, which on decomposition with acid gives $X$ and $\mathrm{Mg}(\mathrm{OH}) \mathrm{Br}$. Which one of the following is $X$ ?

• A

  $\mathrm{CH}_3 \mathrm{OH}$
• Correct answer
  B

  $\left(\mathrm{CH}_3\right)_3 \mathrm{COH}$
• C

  $\left(\mathrm{CH}_3\right)_2 \mathrm{CHOH}$
• D

  $\mathrm{CH}_3 \mathrm{CH}_2 \mathrm{OH}$

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