Serge Watches as Two Lines of Pennies (With Eight Pennies

Multiple Choice

Serge watches as two lines of pennies (with eight pennies in each line) laid out so that both lines are the same length. When asked, Serge says both are equal. Then the researcher takes the pennies in one line and places them farther apart, making that line longer than the other. Now serge says that line has more than the shorter line. What cognitive skill has Serge not yet developed, according the Piaget?

A) Counting.
B) Conventionalism.
C) Centrism.
D) Reversibility