High BP in old age is caused by Calcium def.
Calcium def is often caused by active form of Vitamin D def.
A glass of milk has enough Calcium to make up def.

Conclusion: Some older people can lower their blood pressure by drinking milk.

The physician’s conclusion is properly drawn if which one of the following is assumed?

Note the question stem properly - which one should we assume to properly draw the conclusion i.e. to establish the conclusion i.e. to make the conclusion stand. So we are looking for what is sufficient to make the conclusion hold. We want to establish that drinking milk could lower BP in old people. The calcium def happens because of Vitamin D def. So we should establish that the glass of milk will provide enough active vitamin D along with calcium to lower BP.

(A) There is in milk, in a form that older people can generally utilize, enough of the active form of vitamin D and any other substances needed in order for the body to absorb the calcium in that milk.

Perfect. It says that milk has enough active vitamin D (and anything else that might be needed too) to absorb calcium. So now our conclusion makes perfect sense. A glass of milk should help some elderly lower their BP.

(B) Milk does not contain any substance that is likely to cause increased blood pressure in older people.

It doesn't help establish our conclusion. It is not sufficient to make our conclusion stand.

(C) Older people’s drinking one glass of milk per day does not contribute to a deficiency in the active form of vitamin D needed in order for the body to absorb the calcium in that milk.

Again, a good assumption but not one that will help establish our conclusion. The glass of milk should help aid the absorption of calcium - just not hindering the absorption is not good enough. It must provide vitamin D.

(D) People who consume high quantities of calcium together with the active form of vitamin D and any other substances needed in order for the body to absorb calcium have normal blood pressure.

Doesn't connect milk to vitamin D so doesn't help establish our conclusion.

(E) Anyone who has a deficiency in the active form of vitamin D also has a calcium deficiency.

Doesn't connect milk to vitamin D so doesn't help establish our conclusion.

Answer (A)
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Necessary Vs sufficient condition " is often used in GMAT. The answer choices that GMAT provides are very well in accordance to necessary or sufficient condition. For your reference an article from egmat on Necesary Vs Sufficient consition.
https://e-gmat.com/blogs/gmat-critical- ... onditions/
In the above link there are some OFFICIAL examples discussed too.

Please do not suggest such things. See to it that there is ENOUGH evidence to your claim !!

By the way, I revere LSAT questions. If someone wants to solve then it is a great question. However, I feel that it is not relevant to GMAT.

A is the right answer if you treat it as a sufficient assumption question (which is what you should do as per the question stem). But this is definitely not the right answer for Necessary assumption. Will the argument break if active Vitamin D is not present in the milk and old people get Vitamin D from other food sources? No. Still some older people can lower their blood pressure. This answer choice is correct because it GUARANTEES that some older people can lower their blood pressure but it is definitely not REQUIRED by the argument. This is where difference between necessary and sufficient assumption comes in.

C is wrong because this is a sufficient assumption question. So, the negation test won't work here. The test that you can do here is to see whether the assumption guarantees the conclusion. Only A guarantees the conclusion because it says that active Vitamin D is present in milk, so calcium will be absorbed by old people who drink milk, thereby lowering blood pressure. C does not guarantee that calcium in the milk will be absorbed by the body.

i agree. will option c be a necessary assumption??

thanks
roy

Dear Experts,

Kindly help

generis GMATNinja VeritasKarishma
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VeritasKarishma

Thank you for explaining. So you mean to say that had it been a GMAT question, this option would be correct.
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GMAT and LSAT questions are designed differently. The question stem and the options both would be given as per the test. If you are using LSAT questions to practice for GMAT, you need to understand the differences between the two tests, else it could lead to confusion.
As far as GMAT is concerned, an assumption is a missing necessary premise.
This LSAT question asks you for a sufficient assumption to draw the conclusion. Hence the point of "if this were a GMAT question" does not arise. It is an LSAT question.

ajalil86
Here is a post that talks about the necessary and sufficient statements:
https://www.veritasprep.com/blog/2012/1 ... onditions/
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The argument is as follows-
1) The rise in blood pressure that commonly accompanies aging often results from a calcium deficiency
2) Deficiency is caused frequently by absence of Vitamin D which is required for absorption of calcium
Conclusion- some older people can lower their blood pressure by drinking milk.(Since calcium in one glass of milk can make up for deficiency)

But clearly there is a logical gap here- even if drinking milk can make up for calcium deficiency what about the vitamin D which is required to absorb calcium
without vitamin D there is no use of drinking milk
A) is clearly filling that gap by saying vitamin D is also present in milk which will make drinking milk effective(Vit D + Calcium)