What directly led to the abdication of tsar nicholas ii?

the russians' defeat at verdun
the revolution of 1905
vladimir lenin's return from exile
the garrison in petrograd joining the soviets

Instead of being thirteen republics, under a federal head, [the federalists’ plan] is clearly designed to make us one [unified] government. . whether such a change can ever be [made] in any manner; whether it can be [made] without convulsions and civil wars; whether such a change will not totally destroy the liberties of this country—time only can determine. –the federal farmer what best summarizes the point of view the excerpt expresses? in time, one unified government will run the country. the federalists prefer thirteen republics to one unified government. one unified government probably will not lead to disruptions and civil wars. under one unified government, people will be robbed of their freedoms.