Answer:
1. b) Height of the Roman Empire.
2. d) Fall of roman empire.
3. c) Gregory 1 becomes pope.
4. A) Height of the medieval period.
Step-by-step explanation:
The height of the Roman Empire is usually considered to have happened during the period of the five good Emperors. These emperors were Nerva (96-98 CE), Trajan (98-117 CE), Hadrian (117-138 CE), Antoninus Pius (138-161 CE) and Marcus Aurelius (161-180 CE). During this period, the empire reached its largest extension and a long period or prosperity. However, the fall of the Western Roman empire is considered to have happened in 476 CE. Gregory I became pope in September 3, 590. Finally, the High Middle Ages are considered to have started in 1000 and ended in 1250.