In the passage, the author pitches two competing moral theories against one another. One approach, known as rationalism, links moral sensibility to reason, and towards the end, a second approach links morality to emotion. Also, the author points out that the people promulgating the second approach typically focus on empathy. Hence, the next line of discussion should ideally be centred on the idea of empathy/empathetic concern and how it fares as a basis for explaining moral sensibility. Comparing the options, option C captures this theme correctly. Option C is the answer.The author establishes that psychopaths experience empathy in the first paragraph. (" Like psychopaths, we can dial our empathy up and down; "). Hence, option A does not add much value to the overall discussion.The author does not expand upon the role of fear in the passage and does not provide hints that suggest fear might have a dual role, as stated in option B. Hence, option B can be eliminated.Option D is too narrow. The second camp typically focuses on empathy. Moreover, the author does not explicitly highlight the importance of personal distress anywhere in the passage. Hence, option D can be eliminated as well.