Question

what was the reign of terror?
a time of peace and prosperity in france during the 18th century.
a period when france was ruled by monarchs without opposition.
a period of violence during the french revolution marked by mass executions of enemies of the revolution.
a series of scientific discoveries in france.

Explanation:

The Reign of Terror was a period during the French Revolution. It was characterized by extreme violence. The government used mass executions (via guillotine) to eliminate those seen as enemies of the revolution. This was not a time of peace (so the first option is wrong). France was not under unopposed monarch rule (second option wrong). It wasn't about scientific discoveries (fourth option wrong).

Answer:

A period of violence during the French Revolution marked by mass executions of enemies of the revolution.