Please choose the correct answer to the question: A scientist studies the remains of two extinct animals to learn more about how they lived. She determines that one animal was a carnivore and the other was an herbivore. Which of the following did the scientist most likely compare to make this conclusion?

Answer1: the number of bones in the animals Answer2: the size of the animals Answer3: the body covering of the animals Answer4: the skull of the animals

Answer format: answer1/answer2/answer3/answer4
Answer: answer4