单选题 The passage suggests that an assumption underlying non-economist social scientists dismal of economics as dismal is that

• (A) positive-sum outcomes cannot, by the definition of the power model, exist
• (B) all social sciences founded on pragmatism instead of idealism are dismal
• (C) zero-sum interactions models are inherently optimistic in their view of the future
• (D) scarcity does not necessarily exist as a controlling factor in social systems
• (E) economics is anti-utopian by nature, proposing a more realistic view of the future