What did Constantine do to help reunite the empire? He made Christianity the sole religion, to unite everyone.
He cut the size of the empire to make it more manageable.
He moved the capital to a better location for defense and trade.
He forced all Roman citizens to pledge allegiance to him.

Found this off of google, "Constantine now became the Western Roman emperor. He soon used his power to address the status of Christians, issuing the Edict of Milan in 313. This proclamation legalized Christianity and allowed for freedom of worship throughout the empire. ... In 324, Constantine defeated Licinius and took control of a reunited empire."

So, the answer to your question is D)He made Christianity the sole religion, to unite everyone.

Hope this helps have a great day and stay safe! :) :D :3

Also sorry I was late with the answer.

peasants’ war, (1524–25) peasant uprising in germany inspired by changes brought by the reformation, peasants in western and southern germany invoked   divine law to demand agrarian rights and freedom from oppression by nobles and landlords. as the uprising spread, some peasant groups organized armies. although the revolt was supported huldrych zwingli and thomas müntzerits condemnation by martain luther contributed to its defeat, principally by the army of the swabian league. some 100,000 peasants were killed. reprisals and increased restrictions discouraged further attempts to improve the peasants’ plight.

i think it would be " a" i might be wrong tho