Which finding would most directly support Garza and Robles's hypothesis?

• A. Sea stars in seawater climbed to the top, while those with a freshwater layer did not climb as high.
• B. Both groups climbed to the top regardless of water conditions.
• C. Sea stars in fresh water climbed higher than those in seawater.
• D. None of the sea stars moved.

Answer: (A)

The main idea is that changing salinity affects how the sea stars behave. If their hypothesis is that seawater conditions help them climb more than freshwater, then a result where sea stars in seawater reach the top while those in a freshwater layer don’t climb as high directly shows the environment changing the outcome. It demonstrates a clear link between the water type (the independent variable) and climbing height (the dependent variable), which is exactly what the hypothesis predicts.

If both groups climbed the same amount, or if freshwater led to more climbing, or if none moved, those patterns wouldn’t support the idea that salinity influences climbing performance.