[单选题]A client/server application has been configured to

Atnsnames.ora must be on the client machine for local naming. 

Btnsnames.ora must be removed from the server for the connection to work. 

Ctnsnames.ora must be on both the client and server machines for local naming. 

Dtnsnames.ora is not required for local naming; the problem was not fixed by copying the file to the client.