After Hearing a Story About a Poor Boy Who Gives

After hearing a story about a poor boy who gives a new friend his prized soccer jersey,a six-year-old boy begins to weep.His teacher might explain his behaviour in Piaget's terms by calling attention to the boy's having reached what stage of development?

A) the sensorimotor stage of cognitive development
B) the formal operational stage of cognitive development
C) the preoperational stage of cognitive development
D) the concrete operational stage of cognitive development