In the anion $\mathrm{HCOO}^{-}$ the two carbon-oxygen bonds are found to be of equal length. What is the reason for it?

• A

  The $\mathrm{C}=\mathrm{O}$ bond is weaker than the $\mathrm{C}-\mathrm{O}$ bond.
• Correct answer
  B

  The anion $\mathrm{HCOO}^{-}$ has two resonating structures.
• C

  The anion is obtained byremoval of a proton from the acid molecule.
• D

  Electronic orbitals of carbon atom are hybridised.

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