The treaty of versailles brought an end to world war 1 and placed sole responsibility for the war on which country?

The war was started by the leaders of Germany and Austria-Hungary, Vienna seized the opportunity presented by the assination of the archduke to attempt to destroy its Balkan rival Serbia. This was done in the full knowledge that Serbia's protector Russia was unlikely to stand by and thus may lead to general European war. However, the largest share of responsibility lies with the German government. Germany's rulers made it possible by urging Austra-Hungary to invade Serbia. They also violated international treaties by invading Luxemburg and Belgium knowing that the latter violation was virtually certain to bring in Britain. 

Ithink the answer is c.  hope this is right and