The factor that contributed the most to the population change in the given figure is :
- discovery of gold at Sutter's mill.
Sutter's Mill
- It was a sawmill that was powered by water.
- It was located in California on the banks of South Fork American river.
- It was the site of gold discovery in California.
- It is presently designated as world heritage site.
Discovery of gold in Sutter's mill :
- James Marshall, who was a carpenter in the Sutter's Mill found gold in the South Fork American river.
- Gold was found in the year in 1848 on January 24.
The discovery of gold in the Sutter's Mill area changed the demographic in California.
Thus, the correct option is option (b).
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