PrepTest 110

Incorrect. The stimulus discusses babies with mom as the primary caregiver, which is a subset of babies. As such, this answer about all babies is too broad.

Incorrect. There's no indication that the mom's voice is the "first" thing it can recognize. Maybe it first learns to recognize its primary caregiver's face or smell.

Correct. Argument or Facts:
Facts

Question Type:
Must Be True

Stimulus Summary:
For 4—6wk old newborns with mom as the primary caregiver who are crying:
(1) Mom's voice will stop the crying for a bit
(2) Not—the—mom's voice won't

Answer Anticipation:
This argument compares the impact that two different groups have on a newborn. If the primary caregiver is the mother, then her voice will stop a discomforted baby from crying (at least for a bit). For that same baby, other voices won't.

Note that this is a very strong statement compared to what we might expect. It's not that the mom's voice usually or tends to stop the baby from crying, or that the other voices usually don't. The mom's voice "will" stop the crying for a bit; the other voices "do not" have this effect.

Since the argument uses strong causal language ("lead to" "effect") we can pick an answer that reflects that so let's find an answer aligning with this situation as described.

Answer Explanation:
This answer is backed up by the strong causality in the stimulus. There it's noted that the primary caregiver's voice will cause a stop in crying when the baby is discomforted. That strongly supports the idea that the baby believes that such a voice will lead to it being comforted. While this answer isn't airtight (maybe the same thing doesn't happen with the dad as the primary caregiver) it's reasonably supported by the stimulus and so we can select it for this question stem.

Key Takeaway:
The strength/logical force of statements is one of the key factors in what answers in Must Be True questions are right and wrong. Always be sure to pay attention to the strength of the statements in the stimulus as they'll determine how strong of an answer you can select.

Incorrect. This is a tempting answer choice because the stimulus notes that only the mother's voice will stop the crying for a bit. However, that doesn't mean only the mother can offer comfort—others can feed or change the baby. It's just that the baby doesn't associate other voices with that comfort.

Incorrect. Discomfort in a newborn is probably best relieved by fixing whatever is making it uncomfortable—giving it food, changing its diaper, putting it down for a nap. The mother's voice may help to stop the crying temporarily, but that needs to be followed up by action if the baby is going to be okay! Short version? "[B]est" relieved is too strong.