An analyst does research about marginal benefit and marginal cost. If the government sets a production quota below equilibrium, which of the following statements is most accurate The effect at the quota quantity is that:（）

A. marginal cost exceeds market price.

B. marginal benefit exceeds market price.

C. marginal benefit exceeds marginal cost.

以下不属于建筑工程从业的经济组织是（）

A、施工单位

B、勘察设计单位

C、工程监理单位

D、房地产经济机构