Which of the Following Is Not Correct

Which of the following is not correct?

A) You pay interest on money borrowed to purchase stock on margin.
B) Selling short is selling stock borrowed from a brokerage firm.
C) A call option is the right, but not the obligation, to purchase a stock at a specified price by a given date.
D) A brokerage firm receives double its commission when stock is bought and sold when the investor is selling short.
E) If the stock price decreases and you purchased that stock on margin, you may receive a margin call.