The diagram shows the embryo development of four vertebrates and suggests all of the following EXCEPT
A) common ancestry of vertebrates. (this answer is incorrected)
B) there are no similarities in the embryos of all four groups.
C) there are very few differences in the early development of any vertebrates.
D) common features (gills and segments) in the embryos of all vertebrates.

the oxygenated blood then leaves the lungs through pulmonary veins, which return it to the left heart, completing the pulmonary cycle. this blood then enters the left atrium, which pumps it through the mitral valve into the left ventricle. from the left ventricle, the blood passes through the aortic valve to the aorta.

deoxygenated blood leaves through the right ventricle through the pulmonary artery. from the right atrium, the blood is pumped through the tricuspid valve (or right atrioventricular valve), into the right ventricle.

maritime tropical may be your answer.