Five-Year-Old Rajon Is Playing with His Baby Sister,Andrea

Five-year-old Rajon is playing with his baby sister,Andrea.He takes Andrea's teddy bear and hides it behind a pillow while she watches.Andrea quickly finds the bear.Then Rajon puts teddy in a bag,dumps teddy behind a chair,and then brings out the empty bag.Andrea looks inside the bag,is surprised when it's not there but doesn't look for teddy behind the chair.According to Piaget,Andrea

A) lacks object permanence.
B) is playing to an imaginary audience.
C) is committing the A not B error.
D) is a formal operational thinker.