Larry Notices That His Son Tate Is Having a Great

Larry notices that his son Tate is having a great time playing near the kitchen sink. When Larry asks Tate what he is doing, Tate responds, "It is fun to look at two different size glasses, imagine water pouring back and forth between them, while knowing that the amount of water stays the same even though the glass shapes differ." What do Tate's actions indicate that he has acquired?

A) animism
B) egocentrism
C) irreversibility
D) a mental operation