Convenience -Using single sign-on users have to type their passwords only once when they first log in to access all the network resources; and Centralized Administration as some single sign-on systems are built around a unified server administration system. This allows a single administrator to add and delete accounts across the entire network from one user interface.
The following answers are incorrect:
Convenience -alone this is not the correct answer.
Centralized Data or Network Administration -these are thrown in to mislead the student. Neither are a benefit to SSO, as these specifically should not be allowed with just an SSO.
References: TIPTON, Harold F. & KRAUSE, MICKI, Information Security Management Handbook, 4th Edition, Volume 1, page 35. TIPTON, Harold F. & HENRY, Kevin, Official (ISC)2 Guide to the CISSP CBK, 2007, page 180.