Product ‘C’ in the reaction is,

 $\text{Maleic anhydride}\stackrel{{\text{H}}_{\text{3}}{\text{O}}^{{ }_{\text{+}}}}{\to }\text{(A)}\stackrel{\text{NaOH}}{\to }\text{(B)}\stackrel{\text{Kolbe electrolysis}}{\to }\text{(C)}$

• A

  Propyne

• B

  Butyne

• C

  Ethyne

• D

  Cyclobutane