The best answer is d. The South had more effective military commanders.
As the Civil War began, the Confederacy enjoyed a major geographic advantage: it could fight a defensive war on its own territory. In addition, the South had more experienced military leaders. Some of those advantages were soon countered, however, by the Union navy’s blockade of the major southern ports. On the inland waters, Federal gunboats and transports played an even more direct role in securing the Union’s control of the Mississippi River and its larger tributaries, which provided an easy invasion routes into the center of the Confederacy.
