The first two sentences of D's poem are to recall the past communication with him and express the poet's concern for the prosperous times in the early years of Kaiyuan. The last two sentences are feelings about the decline of state affairs and the erratic artists. The emotional tone of the whole poem should be reflected in the last two sentences, which are slightly negative, but there is no joy. It should be right for A. They should have had friendship in the past. If they don't know anyone, why did Du Fu write about Li Guinian? -I hope the answer helps.