Hi Shantal! –
Nice to meet you online and welcome to Lsatters —
I hope you are finding the Trainer useful thus far —
That question is a really sneaky one, and I’ve been asked about it many times —
I think one way to consider it is to think about the difference between these two phrases:
1) As one gets older, one gets wiser.
2) The older the person, the wiser he or she is.
The difference between those two is very subtle, but one has to do with a person getting older, and the other has to do with older people vs less old people —
If we take them to be true —
The first allows us to infer that Person X will be wiser at 25 than he or she is at 15. However, it doesn’t allow us to infer anything in comparing two different people to one another: If Person X is 25 and Person Y is 10, Person Y can still be wiser, and it wouldn’t violate the given condition.
We know Person X will continue to get wiser as he or she gets older, and Person Y will get wiser as he or she gets older, but we won’t know anything about how they compare to one another.
However, if we take the second statement to be true, and if Person X is 25 and Person Y is 10, Person X must indeed be wiser.
The original argument and answer (D), in their premises, compare different elements (different cities, different trees) and so they are more similar to statement 2, and that’s why (D) is correct.
I hope that clears it up — if it doesn’t, you have any follow-up, or need anything else, just let me know —
Good luck with your studies this week —