Which emerged in opposition to the missouri compromise?
(A)-The national road
(B)-The Calhoun Doctrine
(C)-The American system
(D)-The tariff of 1828

(C) Calhoun doctrine

Explanation: Senator Calhoun was very pro slavery, the Missouri compromise threatened the expansion of slavery making Calhoun part of the opposition of the compromise.

might be agreeing to participate ethically with other european nations in the slave trade

or notifying other european nations when taking possession   of african territories

the answers is b.   environments.