Any cute boys wanna help with my question?

Which was an advantage held by the South over the North at the start of the Civil War?

Question 3 options:

A. It had an industrial economy with limitless immigrant labor to produce weapons.

B. It had far more extensive network of railroads and telegraph lines

C. Its slave population was willing to fight to preserve the plantation system.

D. Its soldiers and generals believed they were protecting their homes and way of life.