Concept:The first stage of learning a skill is imitation, based on the sensorimotor stage of cognitive development.Explanation:Babies learn by observing and copying others' actions.Imitation is the primary tool for acquiring new knowledge in early childhood.This is followed by imagination (preoperational stage), coordination (concrete operational stage), and reality (formal operational stage).Among the given options, only imitation is the correct initial stage.Answer:Option D. Imitation