Soleil (age 8) is presented with two identical balls of clay…

Soleil (age 8) is presented with two identical balls of clay. The experimenter rolls one ball into a long, thin shape; the other remains in its original ball form. Soleil is then asked if there is more clay in the ball or in the long, thin piece of clay. If Soleil answers the problem correctly but cannot use abstract reasoning yet, Soleil is most likely in which stage of Piaget’s cognitive developmental theory?