Professor James will give us a lecture on the Western culture, but when and where ________ yet.[      ]

A. hasn't been decided  

B. haven't decided

C. isn't being decided  

D. aren't decided

“大西柏坡”开发建设既要考虑经济上的投入产出，更要突出精神文化的传承追求。请参考给定资料，就如何挖掘和体现“大西柏坡”独特的精神文化内涵提出自己的建议。

[要求] 理解准确，观点鲜明，条理清楚，切实可行，不超过250字。