Answer: It was the most protected in Petrograd
Step-by-step explanation:
During the October Revolution, the Bolsheviks/ Communists took over the government of Russia from a provisional government that had been put up after the Tsar abdicated.
They started by taking over multiple government buildings in the capital of Petrograd. The government responded by taking refuge in the Winter Palace and reinforcing it with various guards and military students. This forced the Bolsheviks to take it by force after a day.