http://classic.7sage.com/lsat_explanations/lsat-32-section-1-question-20/
This question asks which of following answer choice will strength the conclusion EXCEPT.
The conclusion is that the current map used to show where different types of garden plants will flourish is more useful than the older map.
b is irrelevant because modern station can be over 60 years old as long as the data gathered from them are not 60-year-old!
However I cannot see how does D supports the conclusion? It is assuming the more and better weather data you have, the more likely you can get accurate weather pattern to predict the growth patterns?