The two groups that worked hard as miners and contributed to California's development, even though they faced discrimination were that of the Chinese and the Mexicans.
Answer: Option A
Explanation:
In the initial days after the Chinese had migrated to the US, they were offered to work in the mines in California. Though most of the Chinese had migrated with the idea of working on the farms, textile industries or working as domestic labours, they took up the jobs in the mining fields.
The same was the case with the Mexicans. Both groups worked hard despite having had to face discrimination repeatedly.