The correct options are:
A crowd of about 20,000 people demonstrated in 1905 in St. Petersburg to appeal for workers' reforms. This demonstration led to the Bloody Sunday.
This demonstration along with the Mutiny on the battleship Potemkin (1905) are understood as the first phase of the Socialist Revolution in Russia in early the 20th century.
This series of rebellion against the czar led to the organization of the first soviets, which would be fundamental for the October Revolution 1917. Soviets were councils of organized workers to defend their rights.