Why was the supreme court’s decision in the wabash, st. louis, and pacific railroad v. illinois case an obstacle to state government reform measures?

a. the supreme court ruled that states cannot regulate interstate railroads.
b. the supreme court ruled that states cannot regulate any businesses at all.
c. the supreme court ruled that states cannot regulate manufacturers.

B) The Supreme Court ruled that states cannot regulate interstate railroads.

Just took test :)

was a long, primarily nonviolent series of events to bring full civil rights and equality under the law to all americans. the era has had a lasting impact on united states society, in its tactics, the increased social and legal acceptance of civil rights, and in its exposure of the prevalence and cost of racism. in the south violence and fraud in southern elections from 1868 to 1876, which had reduced black voter turnout and enabled southern white democrats to regain power in state legislatures across the south