Why Was the Standard of Care of a Corporation's Directors

Why was the standard of care of a corporation's directors and officers codified?

A) The law required an objective standard to ensure that fiduciaries strive for perfection.
B) The unduly low common law standard of care compromised the duty of competence.
C) Fiduciaries had to exhibit a greater degree of skill than could reasonably be expected.
D) Fiduciaries were held to an unreasonably exacting duty of competence.