According to Piaget, Preoperational Children Cannot Solve Conservation Problems Such

According to Piaget, preoperational children cannot solve conservation problems such as the "liquids" (or volume) problem because they

A) center on a single perceptual feature or dimension
B) do not yet realize that the transformation they have witnessed is reversible
C) do not understand that changes in one dimension can account for changes in the appearance of another
D) center on a single perceptual feature or dimension and do not yet realize that the transformation they have witnessed is reversible
E) all of these