It would be easier to answer if i could see the grafic from your textbook, but here is some information, hopefully useful:
A. Montana
historically the second largest producer of silver
B. Nevada
-currently the second largest producer of silver - after Alaska
I think that I would go with this answer - was also home to the Comstock Lode, Tonapah and Eureka silver mining districts.
D. California
-has a number of silver mines
