The reason why the Schlieffen Plan was not successful is because the Germans... A.
lost the Battle of the Somme.
B.
lost the Battle of Verdun.
C.
lost the Battle of the Marne.
D.
lost the Battle of Tannenburg.

I think it's C LOST THE BATTLE OF MARNE

Explanation:

because because the battle of Marne was a major turning point in WW1

it is the dominance of   the spanish language and roman catholic region in mexico, french being the official language of several african countries, and the existence of a western-style government in south asian countries