Physics professor: Some scientists claim that superheated plasma in which electrical resistance fails is a factor in causing so-called "ball lightning. " If this were so, then such lightning would emit intense light and, since plasma has gaslike properties, would rise in the air. However, the instances of ball lightning that I observed were of low intensity and floated horizontally before vanishing. Thus, superheated plasma with failed electrical resistance is never a factor in causing ball lightning. The physics professor's conclusion follows logically if which one of the following is assumed?
A: All types of ball lightning have the same cause.
B: The phenomena observed by the physics professor were each observed by at least one other person.
C: Ball lightning can occur as the result of several different factors.
D: Superheated plasma in which electrical resistance fails does not cause types of lightning other than ball lightning.
Choose A, B, C or D as your solution.
A