Final answer:
According to Piaget's theory of development, children learn that things can be represented through words and images during the preoperational stage, which occurs from approximately 2 to 7 years old.
Step-by-step explanation:
The answer to your question is D. Preoperational stage. According to Piaget's theory of development, children learn that things can be represented through words and images during the preoperational stage, which occurs from approximately 2 to 7 years old. In this stage, children can use symbols to represent words, images, and ideas, and they engage in pretend play. However, they cannot understand adult logic or mentally manipulate information.