中晚期食管癌最常见的肉眼形态是（）

A.形成明显的环形狭窄

B.形成较深的溃疡缺损

C.如蘑菇状突入管腔

D.灰白色、质地较软

E.灰红色、质地较软

Which of the following statements about closing a futures position through delivery is most accurate()

A. Delivery is also known as exchange for physicals (EFP). 

B. Depending on the wording of the contract, a trader may close a contract by either delivering the goods to a designated location or by making a cash settlement of any gains or losses. 

C. Although the popularity of physical delivery has decreased over time, delivery by cash settlement remains the most popular method of closing a futures position.