在城市公共财政的职能中，其城市公共财政的首要任务是（）。

A.促进经济建设

B.进行城市的建设和维护

C.推动城市各项社会事业发展

D.保障城市居民生活的基本需求和生活质量稳定提高

They wouldn’t agree to sell the house to us at the same price _____ they had promised, _____ was rather disappointing.

A．which ; as

B．as ; that

C．as ; which

D．that ; that