How should you signal the crane operator to stop in an emergency?（）.

A.Extend arm with the palm down and and hold this position rigidly

B.Place clasped hands in frontof your body

C.extend arm and move hand rapidly right and left with the plam outward

D.Place both fists in front of the body with the thumbs pointing outward

根据《证券公司监督管理条例》规定，（）有权对“了解客户原则”和“适当性原则”制定具体的规定

A．中国证监会

B．中国证券业协会

C．证券交易所

D．国务院