Question

one main factor that led to the holocaust and other campaigns of genocide was
○ extreme racism.
○ emergence of new religious groups.
○ desperate poverty.
○ establishment of a central government.

Explanation:

The Holocaust was driven by Nazi ideology centered on extreme racial supremacy, framing Jewish people and other groups as "inferior" and targeting them for extermination. New religious groups, poverty, and central governments did not serve as the core, direct driver of this genocide or similar campaigns.

Answer:

extreme racism.