The correct options are
A NO−2
B SCN−
C OCN−
D CN−
NO−2, SCN−, OCN− and CN− are all ambidentate ligands as they can coordinate to metal through more than one donor atom.
NO−2 can coordinate to metal through either N or O.
SCN− Can coordinate to metal through either S or N.
OCN− Can coordinate to metal through either O or N.
CN− can coordinate to metal through either C or N.