An unsaturated organic compound, $\mathrm{X}$ on reaction with hot, acidified $\mathrm{KMnO}_4$ gives succinic acid. What is $\mathrm{X}$ ?

• A

  Cyclopentene
• B

  Cyclopropene
• Correct answer
  C

  Cyclobutene
• D

  2-Butene

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