贾诩
Cao Cao faced a dilemma on choosing between his two sons so he consulted Jia Xu, who refused to give an answer. Cao Cao asked him: "Why don't you give an answer?" Jia Xu replied: "I am still thinking about something, so I can't give an answer yet." Cao Cao asked, "What are you thinking of?" Jia Xu replied, "I am thinking of Yuan Benchu, Liu Jingsheng, and their sons." Cao Cao laughed, made up his mind, and designated Cao Pi as his heir apparent.