PrepTest 105, Section 2, Question 12
It is probably not true that colic in(37 more words not shown)
Which one of the following,(7 more words not shown)
- AA study involving(19 more words not shown)
- BSymptoms of colic(24 more words not shown)
- CIn a study(23 more words not shown)
- DWhen mothers of(31 more words not shown)
- EInfants that are(38 more words not shown)
Reading the argument
What if the same antibody can reach a baby through breast milk? The author treats exclusive breastfeeding as a reason to dismiss the cow's-milk-antibody explanation. That works only if breastfeeding actually keeps the relevant antibody out of the picture.
The proposed cause is intolerance of certain antibodies, not simply the act of drinking from a container labeled cow's milk. If those antibodies were also present in breast milk, a baby could avoid cow's milk directly and still encounter the proposed cause.
What we’re looking for
For the weakener, that's my prediction: some connection between breast milk and the antibodies the author wants to rule out. We don't need to identify every cause of colic. We need to show why the supposedly contrary cases might still fit this explanation.
Working the answers
- A
Twins often having colic together doesn't identify the cause. They may share inherited traits, food, or other conditions. The result doesn't isolate the cow's-milk antibodies or explain how exclusively breastfed babies might encounter them. It gives us a pattern without the connection needed to challenge this argument.
- B
Symptoms disappearing with age doesn't establish what caused them earlier. An infant might become better able to tolerate something, or another age-related change might matter. B supplies no reason to reject or accept the antibody explanation specifically. The fact that a condition ends doesn't identify its cause.
- C
More than 4,000 of these 5,000 infants had no symptoms, but we don't know the comparison rate among infants with different exposure. We also aren't told that every infant is unable to tolerate the antibodies. So widespread exposure without widespread colic doesn't settle whether intolerance causes colic in some infants. This study doesn't address the author's breast-milk objection.
- DCorrect
This gives us a possible indirect route through the mother. The babies are still being fed only breast milk, yet their symptoms disappear when their mothers stop consuming cow's-milk products. That connects those products to the very cases the author thought counted against the explanation.
It is more specific than my initial guess that both kinds of milk might contain the relevant antibody. The mother's diet could affect what reaches the infant through breast milk. The answer doesn't prove the exact substance or biological mechanism responsible, but it makes exclusive breastfeeding much less persuasive as a reason to rule out the cow's-milk connection.
- E
Earlier digestive maturity could matter to tolerance, but this doesn't show that the exclusively breastfed babies with colic were exposed to the antibodies in the first place. It also doesn't say whether their symptoms appeared before or after that maturity. Unlike D, it doesn't connect the breastfed infants' symptoms to exposure to cow's-milk products.
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