PT 64 S1 Q6

The number of tornadoes recorded annually inNorth America has more than ... ...

Which one of the following, if true, most helps to resolve the apparent discrepancy described above?
(A) The factors affecting the creation of tornadoes were not well known to meteorologists before 1953.
(B) ...
(C) ...
(D) ...
(E) ...

*This question is included in Oct 2011 LSAT (PT 64): Logical Reasoning A