We have a discrepancy here. The number of recorded tornadoes in North America has tripled since 1953 but meteorologists insist that the climatic factors affecting the creation of tornadoes are unchanged.
This is a Paradox question so we are looking for an answer choice that serves as a possible explanation for this discrepancy.
(E) does just that. If "many more citizens are helping authorities detect tornadoes now than in 1953," this would explain why the number of tornadoes have tripled but the climate factors affecting the creation of tornadoes are unchanged, i.e. it is not that there are actually more tornadoes, we are just better at detecting them since many more citizens are helping.
Hope this helps! Please let us know if you have any other questions.