详解
Choice C is the best answer. The previous question asks how Smith most strongly suggests that slavery affects the United States. The answer, that slavery affects the United States by lowering the country's reputation in the international community, is best supported by the fifth sentence of the last paragraph: "Shall we silently behold the land which we love with all the heart-warm affection of children, rendered a hissing and a reproach throughout the world, by this system which is already tolling the death-bell of her decease among the nations?"
Choices A, B, and D are incorrect because the cited lines don't support the answer to the previous question. Instead, they suggest that because war affects home life, women are right to concern themselves with the possibility of war (choice A), imply that women have a right to consider issues that fall outside the domestic sphere (choice B), and issue a call to action for women to voice condemnation of slavery (choice D).