A student notes question about a study tests whether you can use its results to meet a stated goal. Read the goal first and name what the answer needs to cover: the parts to compare and the effect you must explain. Set aside sentences that don't cover both parts, then check what each group includes and compare the relevant results. Keep different measurements separate, because a change in one doesn't prove the same change in another.
Hints
- Hint 1
The goal asks about both aboveground and belowground parts. Find which parts are present in each tank setup.
- Hint 2
Look for the two outcomes the researchers measured. Which one directly tells you how much sediment stayed in place?
- Hint 3
Compare sediment loss across all three setups. What does each comparison let you infer about the parts present?
Step-by-step
Compare the setups and their results
Step 1Connect the parts to the setups
Start with the relative contributions of eelgrass's aboveground and belowground parts, which asks for each part's role in keeping sediment in place. Which tanks separate those roles? The artificial blades are matched to the live blades in height and density but lack roots and rhizomes, while live eelgrass has both. Comparing the live and artificial tanks helps show what belowground parts add.
- Step 2
Separate current slowing from sediment protection
The currents slowed by 31% and 29% with live eelgrass and artificial blades, respectively, nearly the same amounts. Does that mean they protected sediment equally? No, because current speed and sediment loss measure different things. The claim that blades provide most of the stabilization needs evidence about how much sediment stayed in place.
- Step 3
Use sediment loss to judge both roles
After waves, the artificial-blade tanks lost 38%, while the unvegetated tanks lost 44%, so blades gave some protection without roots. What did the belowground parts add? With those parts present, the live-eelgrass tanks lost 12% of their sediment, 26 percentage points less than the artificial setup. That extra protection points to a substantial role for roots and rhizomes, since current slowing was nearly the same.
- Step 4
Match the claim to the evidence
The goal says accurately characterize what the study suggests, so the answer must not claim more than the results show. Which sentence does that? The wording likely provide some stabilization for blades and substantial additional protection for roots and rhizomes gives both parts a role without claiming an exact share for either. Choice C.