sources.list for security

[Pierre Frenkiel <p.frenkiel@laposte.net>]

hi,

I found several proposals for thre security entry

deb http://security.debian.org/ buster/updates main contrib non-free
deb http://security.debian.org/debian-security buster/updates main 
contrib non-free
deb http://deb.debian.org/debian-security/ buster/updates main

which one must be chosen?

best regards,

Pierre Frenkiel