Roger Is Shown Two Piles of Sand and Says That

Multiple Choice

Roger is shown two piles of sand and says that each pile has the same amount. However, when one pile is flattened with a shovel, Roger now claims emphatically that the flattened pile has less sand. Based on this information, Roger is probably in Piaget's _______ stage of development.

A) sensorimotor
B) preoperational
C) formal operations
D) concrete operations