Which of the following compounds reacts with hydroxylamine to form an oxime, demonstrating significant keto-enol tautomerism?

Step-by-step solution

The compound in option (C) is phloroglucinol (1,3,5-benzenetriol). Phloroglucinol exhibits significant keto-enol tautomerism and exists in an equilibrium with its keto form, cyclohexane-1,3,5-trione. Due to the presence of these active carbonyl (keto) groups in its tautomeric form, it readily reacts with three molecules of hydroxylamine ( NH₂OH ) to form a trioxime. This reaction is a classic chemical proof for the existence of the keto form in phloroglucinol, distinguishing it from the other given phenolic compoun