公司型证券投资基金反映的是（）关系。

A．产权 

B．委托代理 

C．债权债务 

D．所有权

Equilibrium in a perfectly competitive market results in a quantity for which the:（）

A. difference between consumer and producer surpluses is maximized.

B. consumer and producer surpluses are equal.

C. sum of consumer and producer surpluses is maximized.