Violation
For composite resin preparation, cavosurface enamel margins are beveled because (1) a beveled margin produces a more favorable surface for etching (2) a beveled margin improves the edge strength of the composite resin (3) after etching, the bonding agent reduces microleakage (4) the procedure eliminates the need to polish the restoration
(2) (4)
(1) (2) (3)
(1) (3)
All of the above