Violation
To minimize fractures of amalgam restorations in deciduous teeth, cavity preparations should have 1. concave pulpal floors. 2. rounded axiopulpal line angles. 3. rounded proximal retention grooves. 4. lateral walls parallel to the external surface of the tooth.
(2) (3) (4)
(1) (2) (4)
(1) (3) (4)
All of the above.