The correct answer is D. Formal operational stage.
There are stages which are intellectual development for piaget's. For example, Formal operational, , concrete operational, preoperational and sensorimotor which occurs during birth to the age of twenty four years.
Piaget's theory shows development of intelligence of development and the reorganization of mental which results from maturation of biological and environmental experience.
Answer: On APEX your answer will be D.
Explanation:
Unusual or prominent convexity of the abdomen, due to excessive subcutaneous fat, poor muscle tone, or an increase in the contents of the abdomen.