Chemistry - STRUCTURAL ISOMERISM Question with Solution | TestHub

For simple monoketones like butanone (C), the keto form is significantly more stable because C=O and C–H bonds are thermodynamically stronger than C=C and O–H bonds.

In (A), the enol form is phenol, which is highly preferred due to its aromaticity.

In (B) and (D) (1,3-diketones), the enol forms are highly stabilized by conjugation and intramolecular hydrogen bonding.

Therefore, only option (C) has a keto content greater than its enol content.