Which of the following statements about selling shares of stock is FALSE（）

A. The "depth" of the market is typically defined as the number of traders willing to trade at prices above and below the current price.

B. If the initial margin requirement is 50% and the maintenance margin requirement is 25%, the investor who buys a stock at $26 on margin will receive a margin call when the stock hits $17.33.

C. Initial public offerings are sold in the secondary market.

女性，72岁，风湿性心脏瓣膜病40年，近1年服用地高辛(0．25 mg／d)和速尿(40 mg／d)，近日出现恶心、呕吐、心悸、黄视，EGG示：频发室性早搏，遂收入院。本次入院的主要诊断是（　　）

A．心律失常

B．左心衰竭

C．右心衰竭

D．洋地黄中毒

E．AMI