The correct answer is D) to blockade Southern ports along the Mississippi River to cut the Confederacy in half.
The Union's Anaconda Plan was to blockade Southern ports along the Mississippi River to cut the Confederacy in half.
General Winfield Scott had one idea that he shared with other Union's generals: to block maritime ports of the Confederate states to divide the Mississippi River in two and could control the region. This would impede the passing of food, weaponry, and supplies much needed to the Confederated States. The plan was rejected by the Union Army, which rather decided to attack the Confederates.
Most slaves lived on plantations, but the plantations were not very big: they rarely had more than 100 slaves. The best answer is then A. lived on plantations with 20 or more slaves.