In an xinetd config file, which attribute specifies the network address that will be used to offer the service?

Answer: bind

Explanation/Reference:
From the man pages:
bind   Allows a service to be bound to a specific interface on the machine. This means you can have a telnet server listening on a local, secured interface, and not on the  external  interface. Or one port on one interface can do something, while the same port on a different interface can do something completely different.
Syntax: bind = (ip address of interface).