Wrong flaw. This supports a factual claim about the past with a premise that describes what most people believe. The stimulus doesn't rely on people's beliefs as evidence.

(B) assumes that a small change in average salary means there hasn’t been a big increase in the percentage of employees who earn high salaries. This matches the flaw in the stimulus. And like in the stimulus, since averages don’t tell us how changes are distributed, it’s possible that the proportion of high-earners increased substantially despite the average not changing much.

Wrong flaw. This assumes that there hasn’t been a substantial number of new non-apartment buildings built in recent years. The stimulus improperly cites an average to support a claim about how a change is distributed across individuals, whereas (C) doesn't involve a statistical average.

Wrong flaw. This assumes that a change in restaurant menus must cause a change in adults’ weights. Put differently, (D) baselessly assumes a causal relationship. That's distinct from the stimulus, which uses a statistical average to support a claim about a distribution across individuals.

Wrong flaw. This assumes that a change in the proportion of income spent on housing must reflect a change in the average price of housing—it ignores other possible explanations, such as a decrease in income. The stimulus does the inverse, citing a change in the average to support a claim about proportion.