C raccoons because they eat a wide variety because they can adapt more easily than other populations
In this question, there are no options given to choose from. So i would answer this question based on my knowledge. The most likely cause of the observed variation is adaptation and evolution. The birds of that island adapted to the food source and then they evolved as per the requirement of the place and food source.
The reading of the blood pH value of 6.4 indicates a health issue because of the pH value. It is because the concentrations of H+ ions in the body becomes 10 times more than the usual level in the body.
The pH of the blood becomes less than 7.35 due to enhanced production of hydrogen ions by the body or the incapability of the body to produce bicarbonate ions in the kidney, the condition is known as metabolic acidosis that eventually results in acidemia.
The answer should be "Island finches resembled mainland finches, but were not the same species."