An organic compound 'X' having molecular formula C₅H₁₀O yields phenylhydrazone and gives negative response to the iodoform test and Tollens' test. It produces n-pentane on reduction. 'X' could be

Treatment of cyclopentanone


with methyl lithium gives which of the following species ?

Which one is most reactive towards nucleophilic addition reaction?

Reaction by which benzaldehyde cannot be prepared