John Stuart Mill and Kai Nielsen were both utilitarians, but they were different in many ways. We might contrast Mill and Nielsen by saying,
A. Mill was a meta-ethicist and Nielsen was an ethical realist.
B. Mill was a deontologist and Nielsen was a consequentialist.
C. Mill was a rule utilitarian who wished to reform government by basing laws strictly on moral rules benefitting society as a whole, while Nielsen was an act utilitarian who was concerned with justifying actions that seemingly violated 'commonsense morality,' or the conscience.
D. Mill liked Aristotle and the Greeks, while Nielsen thought they were useless.
E. All of the above.