Utilitarianism, in reference to economic fairness, refers to the idea that:（）

A. the greatest good occurs when wealth is equalized.

B. the greatest utility of production and consumption results from competitive markets.

C. equality of opportunity is an important measure of economic fairness.

3个月来因体力活动诱发左前胸及肋骨后压榨样疼痛，并向左肩放射，停止活动后3～5min内疼痛均可逐渐缓解。最可能是：（）

A.变异型心绞痛

B.不稳定型心绞痛

C.主动脉瘤

D.稳定型心绞痛

E.心肌劳损