Trey’s older sister is playing a game with him. She hides the ball they are playing with, and Trey quickly loses interest in the game. He makes no attempt to look for the ball and instead picks up another toy that is close by. This suggests that Trey has not yet developed __________.
a. sensorimotor patterns of responding.
b. a strong attachment to his sister.
c. an understanding of object permanence.
d. the ability to assimilate new experiences.