单项选择题

The passage suggests which of the following about the hypothetical discovery of an absence of seasonal variations in oxygen 18 molecules
Ⅰ. It would not prove that certain dinosaurs were capable of regulating their temperatures internally.
Ⅱ. One likely source of such a discovery would come from annual growth bands of dinosaur teeth.
Ⅲ. The fact that no biotechnology yet exists to elucidate thermoregulation biochemistry proves such a discovery is impossible.
Ⅳ. The discovery would be profound, because oxygen 18 is only found in fossil records where there is seasonal variation.