Final answer:
During the Civil War, although the forces started off with apparent equal strength, the Union's estimated 2.1 million soldiers faced challenges with long supply lines and territory unfamiliarity.option D is correct answer.
Step-by-step explanation:
During the Civil War, the Union and Confederate forces initially appeared to be relatively equal in number and strength. In time, though, disparities became clear. While union armies had to establish long supply lines and faced a daunting task in having to fight on unfamiliar ground and pacify a conquered Confederacy, the South was more positioned and able to mobilize resources and citizens efficiently, including women's mobilization.
Women in the North and South took on various noncombat roles, forming aid societies, nursing wounded soldiers, raising money for supplies, and serving as platform laundresses and cooks within the Union army.As for the numbers represented in the question, Option A is incorrect as it suggests that forces were the same size, which they weren't definitively over the entire course of the war.
Option B is correct in that women were largely limited to noncombat roles. Option C, asserting that nearly 3 million men served in the Confederate army, is incorrect, as that number is too high. The correct statement is Option D, which accurately states that approximately 2.1 million men served in the Union army.