Final answer:
Dinosaur growth rates and longevity were primarily influenced by their metabolisms, which determined how quickly they grew and their life spans. Metabolic rates are closely tied to environmental adaptations and have a direct impact on an organism's growth and longevity.
Step-by-step explanation:
The growth rates and longevity of dinosaurs depended on various factors, but the most compelling option provided is C. metabolisms. Metabolic rates in living organisms are known to directly influence how quickly they grow and how long they may live. Considering examples in biology such as birds, which have high metabolic rates and thus require frequent feeding to maintain energy, we can surmise that dinosaurs with higher metabolisms would also have faster growth rates and potentially different life spans compared to those with slower metabolisms.
When we look at environmental evolution, we see that organisms adapt over time to changes such as oxygen and carbon dioxide levels. During the time of the dinosaurs, there was evidence of lower oxygen availability, which would have influenced dinosaur metabolism and subsequently their growth and longevity. Speciation events, like those leading to the diversity of dinosaur species, are also closely tied to metabolic rates. Hence, while elements like environmental conditions and geological ages certainly influenced their geographic distribution and evolution, the direct impact on individual growth rates and longevity ties back to the metabolic processes of these enormous creatures.