Reaction of cyclohexanone with dimethylamine in the presence of catalytic amount of an acid forms a compound X, if water during the reaction is continuously removed. The compound formed is generally known as

Question

$\begin {array} {1 1} (A)\;\text{An enamine} & \quad (B)\;\text{An amine} \\ (C)\;\text{A Schiff's base} & \quad (D)\;\text{An imine} \end {array}$