Answer:
The correct answer is letter "C": is where children learn abstract thought.
Step-by-step explanation:
Swiss psychologist Jean Piaget (1896-1980) is worldwide known for his Theory of Cognitive Development in which Piaget tried to explain the intelligence development process in human beings according to different age stages. In the formal operations stage -the child is around twelve (12) years-old, humans gain the ability of abstract thinking, reasoning, and planning.