The correct answer is A. Both Kentucky and Maryland were important to the North because they were border states and had vital resources for the war effort.
In fact, those states were slave-states within the Union, as they were highly influenced by the South in terms of economic development.
In Maryland, Baltimore became one of the largest industrial centers of the country during the first decades of the 19th century. The city became the largest manufacturer of ships in the United States during the 1840s, and also a large manufacturer of steam trains. It was there that the first American steam locomotive was built. However, the state's economy still depended in part on agriculture. Maryland allowed the practice of slavery. In 1861 the American Civil War began. The population of the state was divided. Many wanted the secession of the state of the Union and the incorporation to the recently formed Confederate States of America. Others, for their part, wanted the state to remain in the Union.
The Union did not wait for Maryland to decide whether to join the Confederacy. This, because Virginia was one of those who did. If Maryland had done the same, Washington DC, located between the two states, would have been completely surrounded by the Confederation. For that reason, the Union invaded Maryland immediately after the beginning of the war, and for that reason it participated in the war as a Union state. However, many of his men fled and joined the Confederate troops. In 1864 he approved a new Constitution that abolished slavery and imposed severe penalties for those who supported the Confederacy.
Initially, Kentucky declared its neutrality in the war. Officially, however, it was still part of the Union, so Confederate troops invaded Kentucky in January 1862, being expelled by Union forces in October of the same year.
During the war, the population of Kentucky was divided. Many were abolitionists, especially the inhabitants who lived in the main urban centers of the state. Others, mainly farmers, were in favor of the use of slave labor. The abolitionists wanted state participation alongside the Union, and those who supported the use of slave labor wanted Kentucky to join the Confederacy. Even entire families were divided. Nearly 75 thousand inhabitants of the state fought for the Union, and about 30 thousand people fought for the Confederation.
