The statements in (a) and (c) about chlorophyll and the tides are scientific hypotheses, because there are tests to prove them wrong. For example, one may extract chlorophyll from grass and observe the color of the extract and of the remaining grass. One may also try to observe tides that are uncorrelated to the moon's position. The statement in (b) does not have a test that can prove it wrong. It is not a scientific hypothesis.
Work Step by Step
This is similar to the checkpoint exercise on page 10.