Northern transportation industries boomed during the conflict as well-particularly railroads. The North's larger number of tracks
and better ability to construct and move parts gave it a distinct advantage over the South. Union forces moving south or west to
fight often rode to battle on trains traveling on freshly lain tracks. In fact, as Northern forces traveled further south to fight and
occupy the Confederacy, the War Department created the United States Military Railroads, designed to build rails to carry troops
and supplies as well as operating captured Southern rail lines and equipment. By war's end, it was the world's largest railroad
system.
--National Park Service, "Industry and Economy during the Civil War"
Excerpt courtesy of the National Park Service
What can be concluded from the excerpt about the effect of the Civil War on the North?
OA. Some Northern industries benefited greatly from the needs of the Union armies.
OB. Some Northern railroads were captured and used extensively by Confederate forces.
OC. Northern transportation industries were unable to meet the needs of the army.
OD. Northern railroads used freedmen and immigrants to build transportation networks.