Compound `` X `` on reaction with `` O _{3} `` followed by `` Zn `` / `` H _{2} O `` gives formaldehyde and `` 2 `` -methyl propanal as products. The compound `` X `` is :
(A)Pent-2-ene

(B)3-Methylbut-1-ene
(C)2-Methylbut-1-ene
(D)2-Methylbut-2-ene