What is the basis of the researchers' new theory?A.They performed mathematical calculation
What is the basis of the researchers' new theory?
A.They performed mathematical calculations and determined that dinosaurs must have had four chambered hearts.
B.They found a fossil of an entire dinosaur end reviewed the arteries and veins flowing from and to the heart.
C.They found a fossil of a dinosaur's heart and discovered it had four chambers and one aorta.
D.They viewed a fossil of a dinosaur's heart and discovered that it had two aortas.