Which of the following sociology never wrote a book and about whose thoughts most of our knowledge is presented in an edited volume of his lectures published by his students after his death ?

A. Market economies rely on free markets whereas command economies rely on consumer sovereignty
B. Market economies rely on cooperation whereas command economies rely on conflict
C. Market economies rely on privately held property whereas command economies rely on publicly-held property
D. Market and command economies do not differ substantially, but their political institutions do