PrepTest 158, Section 4, Question 11
In the past, infants who were not breast-fed(62 more words not shown)
Which one of the following(8 more words not shown)
- ABoiled cow's milk(15 more words not shown)
- BInfants who consume(13 more words not shown)
- CMother's milk can(5 more words not shown)
- DWhen doctors advised(21 more words not shown)
- EWhen doctors advised(16 more words not shown)
Reading the argument
Boiling the milk might address one problem while creating another.
The doctors wanted to sterilize cow's milk and prevent dangerous infections. I can understand that goal. But what if boiling also affects a nutrient the infants need? Once families widely followed the advice, scurvy became more common. The passage tells us that scurvy comes from a vitamin C deficiency, while breast-fed infants didn't develop it.
What we’re looking for
That sequence makes me suspect that boiling reduced the vitamin C available from the cow's milk. The question asks what the information most strongly supports, so keep that connection in mind while checking the answers. We have evidence about vitamin C availability; we don't have a complete account of every nutrient, every infant's diet, or everything the doctors knew.
Working the answers
- ACorrect
Scurvy became more common after cow's milk was widely boiled, while breast-fed babies didn't develop it. Because scurvy comes from too little vitamin C, that contrast supports the claim that boiled cow's milk supplies less available vitamin C than the same amount of mother's milk.
Notice the answer's limited comparison. We don't have to conclude that boiled milk contains no vitamin C at all. Less available vitamin C can help explain the difference in scurvy without requiring complete elimination of the vitamin.
- B
How frequently did those infections occur? We aren't told. Even if the risk were very rare—say, one case in a million—doctors might want to prevent a potentially fatal infection. Advising a precaution doesn't establish that the danger occurs frequently.
- C
The passage discusses sterilizing cow's milk to prevent infections. It doesn't establish whether mother's milk can cause those infections. A fact about one kind of milk doesn't supply the missing fact about the other.
- D
The doctors could have known that a lack of vitamin C causes scurvy without realizing that boiling the milk would affect vitamin C availability. Knowing the cause of a disease and anticipating this consequence of a recommendation are different things. The outcome doesn't establish their ignorance of the disease's cause.
- E
We don't know the proportions of mothers who breast-fed and those who didn't. It could have been 10 percent or 90 percent; the passage doesn't settle that. A change among infants affected by the advice doesn't establish that most mothers were using cow's milk.
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