In Negligence Cases, the Actions of the Tortfeasor Are Measured

In negligence cases, the actions of the tortfeasor are measured by which standard? ---

A) Whether, under the circumstances of the case, the actor acted as a "reasonably prudent person of ordinary intelligence" would act.
B) Whether, under the circumstances, the actor consciously disregarded a substantial and unjustifiable risk.
C) Whether, under the circumstances, the actor ought to have been aware of a substantial and unjustifiable risk.
D) Whether the actor had a conscious objective to cause the result.
E) None of the above.