One-year-old Jerome is in the stage of cognitive development. Thus, when his mother shows Jerome a ball and then hides it behind her back, we would expect him to . a. sensorimotor; appear to lose interest in the ball and not look for it b. formal operational; appear interested in the ball but not look for it c. concrete operational; appear to lose interest in the ball and not look for it d. preoperational; appear interested in the ball and attempt to look for it