When the United States Barred the Importation of Slaves from Foreign

When the United States barred the importation of slaves from foreign countries,what effect did it have on states like Virginia and Maryland?

A) The prohibition caused the institution of slavery to wither in those states and practically to disappear by the outbreak of the Civil War.
B) The prohibition intensified antislavery sentiment in those states as the importance of slavery in the region declined.
C) The prohibition led the states to shift the focus of their economies away from tobacco and wheat to more lucrative crops such as cotton.
D) The prohibition raised the value of slaves already living in the United States and led to a renewed commitment to slavery in those states.