There was not a lot of freedom in Soviet Union. The State was above the individual and free speech was actually not existent. For sure, the soviets would not allow protests to happen and negotiating would actually show that protesters had some sort of influence over the government. That wasn't desirable. The protests would never be allowed to continue since it was a way to defy the government and diminish it. Soviets are known for radical actions and this case wasn't very different.
b. The Soviets sent their military with tanks to stop the protests.
