You have two $C_6H_{10}O$ ketones,$I$ and $II$. Both are optically active,but $I$ is racemized by treatment with acid and $II$ is not. Wolff-Kishner reduction of both ketones gives the same achiral hydrocarbon,formula $C_6H_{12}$. What reasonable structures may be assigned to $I$ and $II$ respectively?

• A
  $I$ is $3-$Methylcyclopentanone,$II$ is $2-$Methylcyclopentanone
• B
  $I$ is $2-$Methylcyclopentanone,$II$ is $3-$Methylcyclopentanone
• C
  $I$ is $3-$Methyl$-4-$penten$-2-$one,$II$ is $4-$Methyl$-1-$penten$-3-$one
• D
  $I$ is $2-$Ethylcyclobutanone,$II$ is $3-$Ethylcyclobutanone