对外资保险公司监管的前提是（）。

A.外资保险公司经营范围大

B.本国保险市场对外开放

C.本国保险公司数量众多

D.外资保险公司经营范围小

OSI is a theoretical model that shows how any two different systems can communicate with each other. Router, as a networking device, operate at the（）layer of the OSI model.

A.transport

B.application

C.network

D.physical