Professor Wang ,（）for his informative lectures, was warmly received by his students．

A.knowing

B.known

C.to be known

D.having known

某市电信公司提供语音、数据、宽带接入等多种业务。根据《电信条例》及《合同法》的相关规定，请回答下列问题：

若用户申请向该电信公司申请安装有线电话一部，则他与电信公司之间形成的是______关系。

A．雇用

B．委托

C．信用

D．合同