What major event contributed to the signing of the treaty of Brest litovsk

Correct answer is October Revolution.

Explanation:

Treaty of Brest Litovsk between Germany and Russia was signed in March of 1918. Treaty was signed just a couple of months after the October Revolution, during which Russia totally changed its government. New leaders in Russia were craving for peace and that is why at the end they have signed this treaty , according they even lost a lot of territories.

c) they were beaten and fired from their jobs.