Answer:
a. the cause in fact.
Step-by-step explanation:
'Cause-in-fact' is defined as the cause of the result for the action of something. In other words it is the actual cause of the incident.
In the context, Kim's death is the cause of action committed by Joe's negligence driving when he hits the streetlight and the streetlight falls on Joe's head causing his death. It is the negligence action of Joe for which Kim has to suffer. Thus it is regarded as the cause in fact.
Hence the answer is --
a. the cause in fact.