Which Mistake Was Not Made by AECL, the Manufacturer of the Therac-25

Which mistake was not made by AECL, the manufacturer of the Therac-25?

A) It did not include software or hardware devices to detect and report overdoses.
B) It did not tell other hospitals about possible overdose incidents.
C) It reused code without proper testing.
D) It continued to sell the Therac-25 after the FDA declared it to be defective.
E) AECL made all of these mistakes, and more.