What did the Open Door Policy establish? a
Ensured trade with China was equal among the US and Europe

b
Opened trade with the United States

c
Open trade with all nations

d
Ensured trade with Europe

Im not entirely sure if im right but i think its c. Sorry if i get it wrong

the doctrine of nullification recommended that states living inside the union have the one-sided, inalienable ideal to void any law made by the national government that could be esteemed illegal.

the united states was shaped based on a general agreement among its individual states. hence, it is inferred that under the hypothesis of invalidation, since the states are the establishment of the union, they have the ability to referee and disprove unlawful laws.