You work as a database administrator for Supportcenter.cn. You decided to manage client and server connections using Local Naming method in Supportcenter.cn. When you try to connect to the database you get the following error： ERROR：   ORA-12154：TNS：couldnot resolve service name   Which network configuration files would you look into to resolve this error？（）

A. snmp.ora

B. names.ora

C. spfile.ora

D. sqlnet.ora

E. listener.ora

F. tnsnames.ora