B. One
because an independent variable is something you change. So in a scientific experiment you only change one thing. If you happen to change more than one thing then the test becomes unfair therefore you should repeat and make sure that only one thing is changed this time.
Answer: This modern-day researcher used some of the same theories that Darwin proposed. Like Darwin and his finches and tortoises, this scientist understood that the Galapagos cormorants inherited flightless wings. Darwin eventually discovered that his Galapagos finches likely evolved from other species of finches on the mainland. This evolution was similar to how the flightless Galapagos cormorants evolved from other species of cormorants.
Explanation:
<span>The Answer is B: They could use the Benedict's test; it would not have a positive reaction for sucrose but it would for the other three sugars.</span>
