How does the modern era differ from the classical era?

a people mass produce goods using advanced technology during
the modern era that did not exist during the classical era,

b. society has shifted to an agricultural-based economy during the
modern era, but a manufacturing-based economy existed during
the classical era.

c. cultures are more isolated and distinct in the modern era, while
classical cultures around the world shared many more
characteristics.

d. goods are exchanged on a local level during the modern era,
whereas global trade was more prominent in the classical era.