Which of the Following Statements Are Correct Regarding Controls and Calibrators

Which of the following statements are correct regarding controls and calibrators?
1) Controls may not be used as calibrators.
2) Calibrators may not be used as controls.
3) Controls establish correspondence of instrument output signal with known concentration.
4) Calibrators establish correspondence of instrument output signal with known concentration.

A) 2, 4
B) 1, 3
C) 2, 3
D) 1, 4