Herbivorous sauropod dinosaurs could grow more than 100 feet long and weigh up to 80 tons, and some researchers have attributed the evolution of sauropods to such massive sizes to increased plant production resulting from high levels of atmospheric carbon dioxide during the Mesozoic era. However, there is no evidence of significant spikes in carbon dioxide levels coinciding with relevant periods in sauropod evolution, such as when the first large sauropods appeared, when several sauropod lineages underwent further evolution toward gigantism, or when sauropods reached their maximum known sizes, suggesting that ______

Which choice most logically completes the text?

Question

Accepted Answer

the evolution of larger body sizes in sauropods did not depend on increased atmospheric carbon dioxide.

Answer

fluctuations in atmospheric carbon dioxide affected different sauropod lineages differently.

Answer

atmospheric carbon dioxide was higher when the largest known sauropods lived than it was when the first sauropods appeared.

Answer

sauropods probably would not have evolved to such immense sizes if atmospheric carbon dioxide had been even slightly higher.