You'll rack your brain, it'll be on the tip of your tongue, don't take a guess cause that wouldn't be fun there could be many answers but i, m looking for just, one. What am I?

Which two groups worked hard as miners and contributed to california's development, even though they faced discrimination? a.) the chinese and the mexicans b.) the irish and the native americans c.) the french and the chinese d.) the mormons and the mexicans