What do czechoslovakia and yugoslavia have in common?

they were both ancient empires in eastern europe.
they were both located on the atlantic ocean.
they were both created by the treaty of versailles.
they were both on the allied side in world war i.

They were both created by the Treaty of Versailles.

At the end of WWI, the Austro-Hungarian monarchy collapsed. The separation of ethnic minorities was announced during the autumn of 1918 in the cities of Vienna and Budapest. The nationalist movements had been growing for years, and with the weakening of the monarchy they were difficult to contain.

Many countries were created with the collapse of the monarchy. Czechoslovakia and the Kingdom of Yugoslavia were two of these new nations.

They were both created by the Treaty of Versailles.  C THIRD OPTION

b

explanation:

a social contract.

"a social contract is an agreement between citizens and their leader where the citizens give up certain freedoms in exchange for protection. the constitution of the united states is an example of a social contract."