Which of the following statements is true about the characteristics of observers that influence modeling?
a. Older children are reinforced primarily by physical stimuli such as food, affection, and punishment.
b. The set of behaviors we choose to imitate stay constant during our lifetime.
c. The probability of imitation of a modeled behavior is inversely proportional to self-esteem of the observer.
d. Because of immediate imitation during infancy, reiterations of modeled behavior are unnecessary.