310-202 question

Hi guys, i need help :

The system admin wants to configure user_attr(4)sources in the /etc/nsswitch.conf

Which line needs to be configured?

a: passwd
b: user_attr

The answer is A but wait !!

I did a man nsswitch.conf and user_attr is a valid database ( at least for soalris 10) , link here :

nsswitch.conf(4) � configuration file for the name service switch (man pages section 4: File Formats) - Sun Microsystems.

So , why the answer is not B ? The question is old?

Thanks.