What is the conjugate base of chloric acid?

• A

  $\mathrm{ClO}_4^{-}$
• B

  $\mathrm{ClO}^{-}$
• C

  $\mathrm{ClO}_2^{-}$
• Correct answer
  D

  $\mathrm{ClO}_3^{-}$

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