By 1866<span> all states were readmitted into the Union. </span>
The correct answer is A. Class inclusion
Explanation:
Jean Piaget was an important Swiss psychologist mainly known for this theory of cognitive development that involved different stages and developments. In this theory "class inclusion" refers to the ability of children to consider an object or any other element can be included in multiple categories at the same time, for example, a dog can be classified into the category of animals, mammals, pets, domestic, etc. According to Piaget "Class inclusion" is mainly developed in the concrete operational stage (7 to 11 years) because before this, it is difficult for children to consider two aspects of an element at the same time and because of this, they are unable to recognize one element belongs to two categories.
This occurs in the case of four-year-old Meg because she does not consider marbles are classified within glass category and besides this, they can be either striped or white marbles. Instead, she considers glass category as different to marbles and because of this she believes neither strip or white marbles fit into the category of glass and therefore she answers there are more striped marbles.
