Which of the following could be considered a scientific hypothesis?

A scientific hypothesis must be a testable statement that can lead to further investigation or experimentation. The choice indicating that dogs have better hearing than cats fits this criterion because it can be supported or refuted by scientific methods. Research can be conducted to measure and compare the hearing abilities of dogs and cats using various tests, allowing for empirical evidence to verify or disprove the hypothesis.

In contrast, the other options present ideas that are either metaphysical or subjective. For instance, the option about a cat’s spirit being reborn delves into concepts beyond scientific verification, as it deals with beliefs rather than testable phenomena. The statement regarding which pets are "better" relies on personal preferences, making it subjective and not amenable to empirical testing. Lastly, the notion of mind reading involves unverifiable phenomena and does not lend itself to measurable experimentation, aligning it further away from scientific investigation. Thus, the statement about dogs having better hearing stands as a clear, testable hypothesis within the realm of science.