SAT question a44bbd6b (Command Of Evidence)

Question

Several studies of sediment (e.g., dirt, pieces of rock, etc.) in streams have shown an inverse correlation between sediment grain size and downstream distance from the primary sediment source, suggesting that stream length has a sorting effect on sediment. In a study of sediment sampled at more than a dozen sites in Alpine streams, however, geologists Camille Litty and Fritz Schlunegger found that cross-site variations in grain size were not associated with differences in downstream distance, though they did not conclude that downstream distance is irrelevant to grain size. Rather, they concluded that sediment influx in these streams may have been sufficiently spatially diffuse to prevent the typical sorting effect from being observed. Which finding about the streams in the study, if true, would most directly support Litty and Schlunegger’s conclusion?

College Board · Accepted Answer

The correct answer is A. Choice A is the best answer. This finding would support the conclusion. If stream banks are collapsing into the water at multiple points, then sediment is getting into the water at those various points. This supports the conclusion that the inflow of sediment is very spread out.

Explanation

Why the other choices are wrong

SAT Question a44bbd6b: Command Of Evidence answer and explanation

Explanation

Why the other choices are wrong