Final answer:
The Age of Dinosaurs is referred to as the Mesozoic Era, which is option b. It is marked by the presence and eventual extinction of dinosaurs, and it lasted from approximately 245 to 65 million years ago.
Step-by-step explanation:
The geologic time segment known as the Age of Dinosaurs is the Mesozoic Era. This era spanned from approximately 245 to 65 million years ago and included three periods: the Triassic, Jurassic, and Cretaceous. The Mesozoic Era began with the supercontinent Pangaea and witnessed the breakup and drift of continents, changes in climate, volcanic activity, and an abundance of dinosaur species. The Mesozoic is divided into Triassic, Jurassic, and Cretaceous periods, with the Jurassic period being a time of significant dinosaur diversification, often highlighted as the middle period of the Mesozoic Era.
The dominance of dinosaurs during the Mesozoic Era earned this era the nickname 'Age of Reptiles,' which lasted until the extinction event at the end of the Cretaceous period. The Cretaceous-Tertiary extinction event led to the loss of most large-bodied animals of the era leaving only birds as the living descendants of the theropod dinosaurs. In conclusion, the correct answer to the question is b. Mesozoic era.