The reverse "S" curve of the class II amalgam preparation:a.     enhances retention form
b.     makes it easier to restore contact with the proximal tooth
c.     provides a butt joint (90°) of amalgam at the occlusal proximal line
      angle
d.     diminishes resistance form
1)       a, c and b
2)       a, c and d
3)       c only
4)        b and c

2.   Rounding the axio-pulpal line angle will increase the bulk of amalgam
 restoration and prevent stress concentration.
a)             True                     b)    False