According to psychologist Jean Piaget, toward the end of the second year of life, children begin to use words as mental symbols and to form mental images. He referred to this as the stage.

The correct answer is - preoperational.

Explanation:

Preoperational stage is the 2nd stage of the theory of the cognitive development that is presented by the psychologist Jean Piaget. The stage is begins with the age of 2 and ends at the age of 7.

In this stage children use words as symbols and to make imagining ideas and images, in this stage children also start to speak and play games by the help of symbols.

Thus, the correct answer is - preoperational.

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