Which is the most appropriate title for the passage

A．A Comparative Study of the Telecom Industry in China and India

B．Differences on Use of Mobile Phones in China and India

C．Geographical and Cultural Differences between China and India

D．Different Regulations on Mobile Phones in China and India

在派生类中重新定义虚函数时，除了( )方面，其他方面都必须与基类中相应的虚函数保持一致。

A．参数个数

B．参数类型

C．函数名称

D．函数体