Which of the Following Statements Is Most Correct

Which of the following statements is most correct?

A) Because global depository receipts are listed on the London Stock Exchange, U.S.investors cannot buy GDRs through a broker in the United States.
B) Foreign stocks can be traded in the United States if they are registered with the Securities and Exchange Commission.
C) The fourth market is a market for large blocks of listed stocks that operates outside the confines of the organized exchanges.
D) All the above statements are correct.