Answer:
d. conservation.
Step-by-step explanation:
Conservation: The term is given by Jean Piaget, who was a psychologist in his developmental model. He defined conservation in terms of logical thinking abilities of a person that allows the person to distinguish that a specific or particular quantity will remain same in spite of adjustment of the shape, container, or apparent size.
In the conservation stage, a child accomplished that changing the form of an object or substance does not change or hinder its mass, amount, and overall volume.
The term conservation comes under the operational stage of development that lasts from seven to eleven years of age.