某房地产开发企业经过市场调研后，决定在某城市开发供老年人居住的“银发公寓”。那么，开发商在目标市场选择过程中采用的是( )模式。

A．选择专业化

B．产品专业化

C．大量定制

D．单一市场集中化

If you write something and send it immediately by email, which you ___later regret, there is no chance for second thoughts．

A．would

B．should

C．have to

D．might