Answer :
The answer to this is letter D.) It led groups within empires to fight for their political independence. This era sparked lots of revolutions and upheavals against empires; different countries conquered by big empires united and strove to fight for freedom.
I choose letter D.) It led groups within empires to fight for their political independence. Many countries experienced a sense of nationalism where movements sprang out and demanded reforms from the old establishment. Many of these movements would later overthrow the old order and bring changes in the system of government.