Choice B is the best answer. In lines 54-56("of ...mines"), Stanton provides evidence that men are lamenting the problems they have created, as they recognize that their actions have caused "falsehood, selfishness, and violence [to become] the law of life."
Choices A, C, and D are incorrect because they do not provide the best evidence that men are lamenting the problems they have created. Choice A explains society's current fragmentation. Choices C and D present Stanton's main argument for women's enfranchisement.