对于有形产品制造和销售的企业来说，"服务产品组合"中最重要的因素是（）。

A.赠品

B.信息

C.服务

D.有形产品

She            several newspapers but couldn't find the report about the accident.    [ ]

A.looked at              

B.looked for    

C.looked after            

D.looked through