What was notable about the Velvet Revolution in Czechoslovakia? Select two options. It was provoked by union strikes.
The protest leader initially opposed it.
The protests were largely nonviolent.
It began suddenly with mass protests.
The communist leader resigned peacefully.

The protests were largely nonviolent and the communist leader resigned peacefully.

Here's a video on the matter if you're interested:

The Velvet Revolution and Breakup of Czechoslovakia - History Matters

d.prevent the spread of communism outside of eastern europe.

ask google there you might be able to find an answer for the question you're trying to ask