The reagent used in the preparation of aspirin from salicylic acid is

• A

  $\mathrm{SOCl}_2 /$ pyridine
• B

  $\mathrm{CH}_3 \mathrm{COOH} / \mathrm{HCl}$
• Correct answer
  C

  $\left(\mathrm{CH}_2 \mathrm{CO}\right)_2 \mathrm{O} / \mathrm{Conc} . \mathrm{H}_2 \mathrm{SO}_4$
• D

  $\mathrm{CH}_3 \mathrm{Cl} / \mathrm{AlCl}_3$

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