I just used the elimination method:

A it must be, because there is this sentence in the Analects of Confucius.

C because the encyclopedia says that the kindness in Confucius' mouth is only for the nobility, he thinks that "the villain (the poor) is not worthy of kindness."

D Confucius is an educator, who has received countless disciples in his life. It seems that Yan Hui is poor, but he collects it.