The economic and political developments that made slavery a highly con

The economic and political developments that made slavery a highly contested political issue by 1820 included all of the following EXCEPT

A) cotton’s vital role in making slaves much more valuable as either cotton workers or “products” to be sold in the lucrative slave trade.
B) growing hostility to slavery including calls for its immediate abolition by a small, but growing, number of northerners.
C) northerners’ strategic political objections resulting from slavery giving the South a political advantage in the House of Representatives because of the three-fifths compromise in the Constitution.
D) the freeing of many slaves by Virginia and Carolina planters because of the oversupply of slaves on more efficient plantations.

ANSWER
Answer: D