Which event increased workers' unrest on 22 February 1917?

Correct answer: Lockout in a factory

A lockout at the Putilov works in Petrograd increased the anger of workers on 22 February 1917. A lockout occurs when an employer closes a workplace or refuses to allow workers to work, usually during a dispute. In this case, the action worsened existing problems such as shortages, low wages and poor wartime conditions. The next day, women workers joined demonstrations demanding bread and peace, and the protest rapidly expanded. Option A is correct because the factory lockout directly intensified labour unrest. The tsar’s birthday, a Duma election and bank nationalisation were not the immediate event described in this sequence.