The U.S. Department of Agriculture divides the North American continen

Responding to a pm:
There is absolutely no ambiguity in this question.

Premises:
- Hardiness zones are based on the average winter temperature and are used to determine what types of plants will likely survive in a given area.
- Zone 1 represents the coldest average winter temperature and zone 13 the warmest.
- The zones are correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season - probably colder means shorter growing season from common knowledge
- Minneapolis is in hardiness zone 4 and Denver is in hardiness zone 6.

A. During the coming winter, the lowest recorded temperature in Minneapolis will be lower than the lowest recorded temperature in Denver.
We only know about average temperatures, not lowest.

B. The growing season in Denver is much longer than the growing season in Minneapolis.
Hardiness zones do not match the eleven "length of growing season" zone.

C. A greater variety of plants can be grown in Denver, due to the warmer average winter low.
No information about whether more variety survives in warm climate or cold - we will not use our general knowledge.

D. Factors other than average winter temperature affect the length of the growing season.
It is given that zones are correlated but DO NOT match exactly. It means other factors also come into play. Correct answer.

E. At least one U.S. city has a colder average winter temperature than does Minneapolis.
If you feel that "city" vs "area/town/piece of land" is nitpicking, then that's not correct. Perhaps a small wild piece of land right next to Canada lies in the hardiness zones 1, 2 and 3. Perhaps only some forest/mountain region lies in the first 3 zones. Perhaps no city lies in these zones since a city invariably ends up being warmer than the wild due to industrial activity. We don't know.
- But more importantly, North American continent includes not just US but also Canada and Mexico. Hence, even if you ignore the difference between city/town etc, nothing says that a US city must lie in first three zones. US and North America are not interchangeable!

@ original poster : i am really doubting this question !!
i do not find any reason to reject option E : At least one U.S. city has a colder average winter temperature than does Minneapolis.
can u please check the choices again

There is nothing that implies that the "zones" are cities. They are just areas.

so Denver and Minneapolis are areas !! not cities ?? after all some area will definitely comprise some city

Just as 1 city can comprise multiple hardiness zones (particularly if the city is big enough).

A) Passage talks about average temperatures, not lowest, so can't be A.

B) Could be true, but it says close correlation not exact. We'll leave it as a possible choice for now since it's vague.

C) Nothing in the passage suggests this.

D) The fact that length growing season and average winter temperature both have SEPARATE zones which are not exactly the same indicates that these 2 are not determined by the same factors. Strongest contender.

E) Minneapolis is 4, but passage does not suggest any other CITY is less than 4. Could be town, village, inland water body. First sentence says it's a division of the continent, not a division of urban agglomerations.

I am in the same boat as you are in. I chose E too and was in for a shock. The source is Veritas Question Bank.

i will not be worried about this question as long as it is not official !! i do not think GMAC will ever get into the nitpicking of "area", "city" or "town"
also if someone is putting a logic that "cities" can be large enough to comprise more that one zone then the same argument can be put on the other side of story !! i mean why should we favor one side of the argument?

also if cities such as "Minneapolis" and "Denver" can have just one "zone" then we can definitely have other cities with just one "zone" ,after all there are cities smaller than Minneapolis !! (honestly i don't even want to get into this side of argument)

Every word matters! Small differences in meaning can change the whole question!

The U.S. Department of Agriculture divides the North American continent into “hardiness zones.”
These zones are based on the average winter temperature and are used to determine what types of plants will likely survive in a given area.
Zone 1 represents the coldest average winter temperature and zone 13 the warmest.
The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season.
Minneapolis is in hardiness zone 4 and Denver is in hardiness zone 6.

Which of the following statements is most supported by the information above?

A. During the coming winter, the lowest recorded temperature in Minneapolis will be lower than the lowest recorded temperature in Denver.............we can infer that avg winter temp is lower but not lowest. new info.

B. The growing season in Denver is much longer than the growing season in Minneapolis...............this is new info as we don't any info in argument regarding growing season.

C. A greater variety of plants can be grown in Denver, due to the warmer average winter low..............we can decide type of plant in area based on zone avg winter temp not greater or fewer variety of plants.

D. Factors other than average winter temperature affect the length of the growing season..............can be true keep it at bay.

E. At least one U.S. city has a colder average winter temperature than does Minneapolis.............this cannot be inferred as atleast one city has a colder avg temp than does Minneapolis as the zones are divided among whole North American continent.

Woul you please explain a little bit about it? How other factors come to play?
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The argument gives you
"The zones are closely correlated with, but do not exactly match another set of eleven zones that indicate the length of the growing season. "

If the only factor that affected the length of the growing season was average winter temp, then the zones of length of growing season would have exactly matched the zones of temperatures. But the question tells us that they do not exactly match. So other factors such as "topography" could be playing a role in deciding the length of the growing season.

Veritas Prep Official Solution:

Correct Answer is D.

This question illustrates a crucial logical principle: in order to show that an answer choice is incorrect on a “must be true” question, you do not need to show that it is “certainly not true”. All you have to do is come up with one example (which is often quite difficult) in which the conclusion is not true. On inference questions, it is unlikely that you will pick a “must be false” answer when you are asked for something that “must be true”. However, it is entirely possible that you will pick something that is likely to be true but not guaranteed to be true.

In this question, most of the incorrect answers are likely but not guaranteed. It is quite likely that, as choice A states, Minneapolis will have a lower extreme temperature than will Denver. Similarly, it is likely true that Denver has a much longer growing season. But neither is necessarily true. Denver has a higher average temperature, but that could be a result of shorter, colder winters and a quicker jump back to spring. And regarding choice B, the zones "do not exactly match" the length of the growing season, and Denver or Minneapolis might be one of those exceptions. Nothing states that the hardiness zones are associated with variety so choice C can be eliminated because of this fact.

For the most difficult incorrect answer - choice E - it seems that there must be a colder city since Minneapolis is only a four on a one to thirteen scale. However this scale is not just for cities and it is for all of North America, not just the U.S. It could very well be that the coldest city is a 4 (Minneapolis!) and only other rural areas or place outside of the U.S. are given lower ratings. D, however, can be proven: if the zones are not identical, then there must be another factor that accounts for the difference between hardiness zone and length of the growing season.

I am confused about the OA. I understand that zones need not be cities, and hence option E is incorrect. However, how can we say that factors other than average winter temperature affect "length of growing season". What if the zones for "length of growing season" are exactly based on hardiness zone but three zones were clubbed together because there really isn't much difference between those zones in terms of length of growing season?

Could you clarify this point?

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