Investigators have not proved that the forest fire was started by campers. ... ...

Investigators have not proved that the forest fire was started by campers. Nor have they proved that lightning triggered the fire. So the investigators have not proved that the blaze was caused by campers or lightning. The flawed pattern of reasoning in which one of the following arguments most closely resembles the flawed pattern of reasoning in the argument above?
(A) Kim has no reason to believe that Sada will win the election. Kim also has no reason to believe that Brown will win the election. So Kim has no reason to believe that either Sada or Brown will win the election.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in June 2013 LSAT (PT69): Logical Reasoning A