The class decided to humanely euthanize the organism and subsequently dissect it. Having decided that it was probably not a reptile, two of their original hypotheses regarding its identity remained. Which of the following, if observed, should help them arrive at a conclusive answer?A) Presence of a closed circulatory systemB) Presence of moist, highly vascularized skinC) Presence of lungsD) Presence of a nerve cordE) Presence of a digestive system with two openings