Answer:
pretty sure it's d not sure also might be b but I think it's d
Halite and sulfur are the two minerals that you can taste and identify. Halite has a salty taste on it and Sulfur has a rotten egg taste. I would rather taste Halite more than Sulfur.
So that later in time (or present day) it could be changed to fit better with the social, political, and economic changes of the US and the world.