Answer:
D. The creation and spread of written language
Step-by-step explanation:
THe classical period of the Human History goes from the 600 BCE to the 600 CE, this marks a widely spread of empires and cultures that grew larger than ever, the greatest and largest Roman Empire was seen in that era, and one of the main characteristics from that period was the spreading of written language and the creation of more advanced civiliations with tendencies to phillosophy, ethics, confucius is one of the landmarks that initiates the classical period. THe period comes along with an assurance of food and crops, this meant that human kind was able to focus on other sciences like arts, math and literature.