Physician: The rise in blood pressure that commonly accompanies aging

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)