Why Would an Antifascist Coalition Government Such as the French

Why would an antifascist coalition government such as the French Popular Front have been impossible in democratic countries before 1936?

A) Stalin had just reversed his ban on international Communists participating in coalition governments.
B) That year saw the defeat of the antifascist republicans in Spain.
C) That was the year that the League of Nations agreed to allow the formation of multiparty coalitions.
D) No one recognized that fascism was a growing danger until that year, when Hitler unveiled his new army and air force.