The orifice of the parotid duct is located______________?

A. It prevents the formation of copper oxide
B. It prevents the formation of chromium oxide or dissolves chromic oxide layer
C. It prevents the flow of material in undesirable area
D. Increase the strength of solder

A. They have a modulus of elasticity twice that of gold alloys
B. They are more rigid than gold alloys
C. They have higher ductility than gold alloys
D. They have a lower proportional limit than gold alloys