As a rule, a preoperational child who is asked which row of coins "has more" answers that the longer one has more (even if the two rows both have seven coins) . What kind of experience is most likely to enable the child to give the correct answer?

A) First test the child on conservation of weight and conservation of volume tasks.
B) First ask the same question about rows of three coins each.
C) First let the child spend an hour playing with coins.
D) First give the child a lecture about the properties of the number system.

Asking the same question about rows of three coins each would allow the child to compare and contrast, and likely recognize that the physical length of the row does not necessarily determine the quantity of coins. This task allows for concrete experience rather than abstract concepts, which would be more relevant to a preoperational child's level of understanding. A lecture or conservation tests may not be as effective in promoting correct understanding in this case, and spending an hour playing with coins may not necessarily provide the necessary guidance or instruction for the child to develop an understanding of quantity.