For how many years did the reign of terror last? one three five seven

The correct answer is: "one year".

The Reign of Terror is the denomination given of a period of French history comprised during the First French Republic, which was established after the French Revolution. It started in 1973 and ended in 1974 with the execution of Maximilien Robespierre, one of its main outstanding figures. The origin of its name can be evidenced in the fact that during this year 16,594 official death sentences were issued in France.

answer; the president uses mass media to gain support for policies;