Which of the following statements is true about heat-treatable alloys? A Heat-treatable alloys are those that cannot be hardened by quenching. All...

Which of the following statements is true about heat-treatable alloys?

A Heat-treatable alloys are those that cannot be hardened by quenching. Alloys that cannot be heat treated are usually hardened by precipitation.
B Heat-treatable alloys are those that can be hardened by quenching. Alloys that cannot be heat treated are usually hardened by precipitation.
C Those that cannot be heat treated are alloys that can be hardened by quenching. Heat-treatable alloys are usually solubilized and hardened by precipitation.
D Those that can be heat treated are alloys that can be hardened by quenching. Alloys that cannot be heat treated are usually solubilized and hardened by precipitation.
A
B
C
D