Final answer:
The revolt that Martin Luther urged to suppress was the German Peasants' War (Option A).
Step-by-step explanation:
The revolt in the 1520s that Martin Luther urged the nobility to suppress quickly and ruthlessly is known as the German Peasants' War. This conflict occurred within the context of the broader religious upheavals of the Reformation period.
Although Luther initially sparked significant change with his critiques of the Catholic Church, which led to the Protestant Reformation, his stance during this war surprised many because he backed the suppression of the revolting peasants, who were largely inspired by the new egalitarian religious ideas Luther himself had propagated.