Test Analysis: This question examines the relevant contents of Kaiyuan Shi Sheng. "Kaiyuan" is the title of Xuanzong in Tang Dynasty. In the early days of the reign of Emperor Xuanzong of the Tang Dynasty, the social economy was prosperous and the national strength was strong, and it was known as the "Kaiyuan Shi Sheng". This poem by Du Fu is a scene of a prosperous new century, so the answer is D.