Which of the following statements describes the overall conclusions regarding the weak-form of the efficient market hypothesis (EMH)（）

A. All evidence indicates that simple trading rules generate positive abnormal returns.

B. Stock exchange specialists using monopolistic information contained in the limit order book derive above average returns.

C. Most evidence indicates that after incorporating trading costs, simple trading rules do not generate positive abnormal profits.

电路板的设计验证包括多种检查，其中以电路连通性的检查和安全间距的检查最为重要。