using GPL program through different interfaces by another program and that program license issue

[pretor_hq at wp.pl]

Dear Sirs

If there is GPL  Program A with
a) command line interface (ie c:\progA.exe someCommand)
b) telnet interface (ie c:\progA.exe connectToTelnetInterface  and after 
that I can just do some commands ie #command1 )

and if there is a program B which uses a) interface (invokes the 
command) then does B had to have GPL license or not?

and if there is a program C which uses b) interface (invokes the the 
command which connects him to telnet interface of A and after that 
invoking some A telnet commands) then does C had to have GPL license or 
not?

Regards