详解
Choice B is the best answer. The previous question asks what point Grimké makes about human rights in Passage 2, with the answer being that they exist and have moral authority whether or not they are established by societal law. This is supported in lines 61-65: "These rights may be wrested from the slave, but they cannot be alienated: his title to himself is as perfect now, as is that of Lyman Beecher: it is stamped on his moral being, and is, like it, imperishable."
Choices A, C, and D are incorrect because the lines cited do not support the answer to the previous question about the point Grimké makes about human rights in Passage 2. Instead, they explain the source of all people's human rights (choice A), indicate what would happen if rights were determined by gender (choice C), and discuss why gender is irrelevant to rights (choice D).