What Major Issue Challenged the Stability of the Weimar Republic

What major issue challenged the stability of the Weimar Republic from the beginning?

A) The Weimar government refused to grant women the right to vote, so more than half the population of Germany never supported the government.
B) The Weimar government relied on street violence, paramilitary groups, and protests rather than parliaments to solve political problems.
C) The Weimar government was made up of many former military leaders, but the German population deeply distrusted the military and did not see the new government as a legitimate authority.
D) Weimar leaders refused to sign the Treaty of Versailles, which angered the vast number of Germans who just wanted to end the war, whatever the cost.