下列各项中，属于房地产开发活动的是（）。

A.土地开发

B.房地产开发

C.住宅开发活动

D.房屋销售

The number of the people in Nantong ______ than ______ in Shanghai.

A．are smaller, those

B．is smaller, those

C．is smaller, that

D．are smaller, that