Dr. Grant is conducting an experiment to see if female cockatoos of a certain species prefer males with red feathers on their heads. In her experiment, she paints the feathers on several male cockatoos' heads four different shades of red. She then releases the painted cockatoos and monitors how many females each male attracts.
Question: What's wrong with Dr. Grant's experiment?

a.) she did not release any normal cockatoos and monitor them.
b.) she did not test multiple males.
c.)s he did not monitor the painted cockatoos after they were released.