Based on Peter Singer's arguments in "Famine, Affluence, and Morality," the answer that fits best is:
D. The present way we distinguish between duty and charity cannot be supported.
Singer argues that the traditional distinctions we make between what we consider a moral duty and what we see as acts of charity are not morally justified. He challenges the notion that we are only obligated to help those in our immediate community and asserts that we have a moral duty to assist those in need, regardless of their location.