In determining the ideal proximal outline
form for a Class II amalgam cavity
preparation in a molar the
1. axial wall should be 1.5mm deep.
2. gingival cavosurface margin must
clear contact with the adjacent tooth.
3. proximal walls diverge occlusally.
4. facial and lingual proximal
cavosurface margins must just clear
contact with the adjacent tooth.

(2) and (4)

(1) (2) (3)

(1) and (3)

All of the above.

(4) only