Three of the Following Teaching Practices Are Consistent with Piaget's

Three of the following teaching practices are consistent with Piaget's theory of cognitive development.Which one is not?

A) When Sue leaves out important details as she tries to explain something, her teacher says, "I don't understand what you mean when you say...."
B) A second-grade teacher encourages students to speculate about possible explanations as to why kites can fly, and then to test each explanation systematically.
C) When a high school student claims that people should "Make love, not war," his teacher urges him to consider whether such an approach would have been advisable when the Fascist movement was gaining ground in Europe in the late 1930s and early 1940s.
D) When Martin says that two nickels are worth more than one dime because there are two of them and they're bigger, his teacher asks, "How can that be? Two nickels are worth ten cents; one dime is also worth ten cents."