What was Frederick Douglass contribution to abolitionism?

He became a leader in the abolitionist movement, which sought to end the practice of slavery, before and during the Civil War. After that conflict and the Emancipation Proclamation of 1862, he continued to push for equality and human rights until his death in 1895.

Explanation:

the navigation act prevented the colonies from exporting to countries other than britain and it prevented the importation of goods by other countries as well. so i believe the correct answer is d. other nations could not deliver goods to the colonies.

hope this .