Jack sees jill falling down a hill. At the bottom of the hill, Jillis tumbled over, and clearly endured serious injury. However, while it is not the most ethical conduct, Jack is in a rush and does not feel like helping Jill, Jill attempts to sue Jack for negligence. Which element of negligence will fill most likely be unable to prove?

a. Duty - under the bystander rule, Jack is under no legal obligation to help ill.
b. Breach- Jack had a duty to help jill that he failed to meet by not coming to her rescue
c. Causation because Jack did not help Jul, she was hurt
d. Harm - Jill suffered harm as a result of Jack's negligence