The correct answer is, B and D.
Another way to say it is the correct answer is Aristarchus was not as famous as Aristotle and Aristarchus could not answer some important questions about the model.
Aristarchus was not as famous as Aristotle. Aristotle's model was more accurate. Aristarchus could not answer some important questions about the model. Aristarchus had fallen out of favor with Alexander the Great. Aristarchus was not as famous as Aristotle. Aristarchus could not answer some important questions about the model.