I love everything about these. I love the focus on everyday people who overcame a lot of the same issues that we new test takers go through, and became giant's of wordsmithing and language.

I really don't like the idea of A.) being wrong because it still leaves room for small families being smaller or Large Families becoming smaller large families or small families. The stimulus draws a correlation between family size and likelihood of allergies. It doesn't just draw a simple distinction between two family types (small and large) and says "okay. you've now entered into a nebulous definition of a small family - this is now sufficient to being prone to allergies".

This is a correlative relationship not a logical relationship.

We're approaching this like the latter by eliminating answer A.) on the basis of not knowing if family sizes in this country are small or still large after the average decline in family size.

Small Family -> Prone to Allergies

/Prone to Allergies -> /Small Family

This is not an appropriate approach to relationships of a correlative nature.

Additionally, in the explanation video, EY points out that the stimulus only points out the correlation found in infants, and answer choice A.) highlights incidents of allergies in general, but neglects incidents in infants. However, this is false. The hypothesis in the stimulus specifically mentions that exposure during infancy makes people less likely to develop allergies, not just infants. This led me to pick answer choice A.) due to the fact that answer choice E.) refers only to allergies in children less than age one and children not less than one.

Answer choice E.) requires us to assume that:

• Most day cares are sufficiently large enough of a pool of children to mimic the aspects of a larger family on infants.

• The children being sent to daycare after infancy are being sent to daycares of roughly equal size to the ones being sent during infancy.

• Children spend enough time in day care to be exposed to the full breadth of germs as children living full time with other children are.

• We fully understand the age range that is classified as infancy (1 year < less).

• The Small families that sent their kids to day care after infancy, were of equal "small" size to the ones that sent them during infancy. (The same reason we eliminated A.).

• Daycares would allow the same sanitation standards of a larger family (that is to say not sanitary enough causing the mitigation of allergies).

Granted, the day care scenario creates a rough experiment between two samples of small families, however Answer choice A.) compares families at one or more earlier points in time and families at one or more later points in time. Incidents of allergies at earlier points were less prevalent when families were larger (not definitively "large" or "small").

Just because we're taught to create the perfect experiment by comparing two similar or identical sample sets, doesn't preclude that charting an x (independent) variable (time) and a y variable (size of family) overlaid by the prevalence of allergies is a potentially superior method of proving this point. Not in spite of the century of tracked data, but especially because of the large breadth of time to track these changes. That is, if the span of the study was only over the course of a year, this would critically weaken A.)