When should oral hygiene begin to be performed on children?

A) When they begin eating solid foods
B) When their primary teeth become visible in the oral cavity
C) Only when the infant allows you to clean their mouth
D) Even if no teeth are present, the gingival ridge should be wiped

D
Explanation: D) After feeding, the ridges where the teeth will appear and the palate should be gently wiped with gauze or a soft washcloth. This removes leftover food and establishes a routine for the mother to clean inside the child's mouth.