The treaty of versailles included a “war guilt” clause that

Placed sole responsibility for the war on Germany, is the right answer.

Explanation:

The Treaty of Versailles punished Germany. The vanquished nation suffered abundant territory and had harsh limitations fixed on its armed operations. As unfavourable as these prerequisites were the most disturbing was Article 231. This article is recognised as the "war guilt" clause. This clause placed sole accountability for the war on Germany. Consequently, Germany had to meet reparations to the Allies.

i think your answer there is c

a.   it resulted in widespread unemployment.