Question

russian revolution
what marked the end of the russian monarchy?
the russian civil war
the russian revolution
the execution of the tsar and his family
the tsar and his family’s ... to siberia

Explanation:

The Russian Revolution (specifically the February Revolution in 1917) led to the abdication of Tsar Nicholas II, ending the Romanov dynasty and the Russian monarchy. The Russian Civil War came later, the execution of the tsar and family was a later event of the revolution's aftermath, and exile to Siberia wasn't the end - marker.

Answer:

the Russian Revolution