What is X in the following change ?

• Correct answer
  A

  $\mathrm{CH}_{3} \mathrm{OH}, \mathrm{H}_{2} \mathrm{SO}_{4}$
• B

  $\mathrm{CH}_{3} \mathrm{OH}, \mathrm{CH}_{3} \overline{\mathrm{O}} \stackrel{+}{\mathrm{Na}}$
• C

  $\mathrm{H}_{2} \mathrm{O} / \mathrm{H}_{2} \mathrm{SO}_{4}$ followed by $\mathrm{CH}_{3} \mathrm{OH}$
• D

  $\mathrm{CH}_{3} \mathrm{MgBr} / \mathrm{H}_{3} \mathrm{O}^{+}$

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