Answer:
The answer is the formal operational stage.
Step-by-step explanation:
During this stage, the fourth and last according to Piaget's structure of cognitive development, people begin to think logically. Another key feature is the development of abstract thought, which also involves creativity.
In the example, the child has developed the ability to imagine a world that's radically different from the real one; thinking about hypothetical situations are characteristic of the formal operational stage.