The owner of the cinema needed to make a lot of improvements and employ more people to keep it running, __________ meant spending tens of thousands of pounds.

A．who

B．that

C．as

D．which

维系和挽留是在（）的基础上，根据不同的状态和（），提供通信内和通信外的差异化服务和针对性的市场策略，稳定和提高客户忠诚度，达到稳定在网、提高价值的目的。