According to Dunn's Research, Which Mothers Are Most Successful at Promoting

According to Dunn's research, which mothers are most successful at promoting positive behaviours that their older children direct toward their younger sibling?

A) mothers who give the older child extra, focused attention and are sympathetic to the older child's brooding or negative responses
B) mothers who begin to reduce attention to the older child before the birth of a sibling to desensitize them to the coming events
C) mothers who give the older child quality time and actively discourage negative responses toward the infant
D) mothers who explain to the older child that negativity will not be tolerated and actively punish any negative responses