Why Did the Republican Forces Lose the Spanish Civil War

Why did the republican forces lose the Spanish Civil War despite the popular outpouring of support for the cause of democracy from around the globe?

A) Although the republicans had strong support from European governments, squabbling among British and French military leaders led to poor strategic decisions that cost republicans the war.
B) Once Stalin pledged his support to the republican cause, anti-Communist members of the republican forces abandoned the coalition and joined the rebel forces.
C) As their appeals for material aid went unheeded by European democracies, republican troops floundered in the face of Franco's army, which was supported by Hitler and Mussolini.
D) Despite global support for the cause of democracy, the legendary atrocities committed by republican forces eroded support for their cause among the Spanish population.