In Studies of the Development of Jealousy

In studies of the development of jealousy,

A) younger children expressed jealousy of a sibling receiving parental attention, but older children did not.
B) no changes in the expression of jealousy occurred across development.
C) younger children displayed distress in response to jealousy-provoking scenarios, whereas their older siblings displayed anger and sadness.
D) children who reacted with jealousy were more able to focus on play activities than children who showed less jealousy.