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Percent changes compound multiplicatively, not additively. Choose a convenient baseline, e.g., 100 units in 2023. A 20%20\% increase to 2024 multiplies by 1.201.20, yielding 120120. A 25%25\% decrease to 2025 multiplies by 0.750.75, yielding 120×0.75=90120 \times 0.75 = 90. Compared with the original 100100, the final amount is 9090, which is a −10%-10\% change overall. Choice A is correct. Choices B and D come from adding +20%+20\% and −25%-25\% to get −5%-5\% or mistakenly averaging signs, but the correct method is multiplication of growth factors. Choice C (−5%-5\%) is a classic trap from linear (non-compound) thinking. On the PSAT, treat consecutive percent changes as products of factors: 1+r1 + r for increases, 1−r1 - r for decreases (where rr is decimal). This approach also highlights asymmetry: a 25%25\% drop from 120 is 30, which more than offsets the earlier gain of 20 from 100. As a general rule, to “undo” a p%p\% decrease, you need an increase of p100−p×100%\frac{p}{100-p}\times 100\% (e.g., a 25% decrease requires a 33⅓% increase to get back), reinforcing why sequential changes can’t be summed directly.