TOEFL Listening: TPO-TOEFL听力TPO - OB4V2VI7DQ1T1UI4R$

What does the professor imply about the history of Hailey's Comet? A. Hailey's Comet did not always have the same orbit it has now B. Hailey's Comet used to be much smaller than it is now C. Hailey's Comet has always had the same orbit that it has now D. Hailey's Comet is much younger than the rest of the solar system