Eighteen-Month-Old Mickey Is Visiting a Theme Park for the First

Eighteen-month-old Mickey is visiting a theme park for the first time. At the park, he sees some zebras, an animal with which he is unfamiliar. Despite this, he looks at the animals and shouts, "Look at the horses!" He had previously formed a mental schema for horses. Piaget would say that Mickey's reaction best demonstrates the concept of

A) accommodation.
B) reversibility.
C) assimilation.
D) formal thought.