Electronic Communication Networks (ECNs) ________

Electronic communication networks (ECNs) ________.

A) are not a limit order book.
B) offer transparency, anonymity, automated service, and reduced costs, and are therefore effective for handling small orders.
C) may not be linked into the Nasdaq marketplace via a quotation representing the ECN's best buy and sell quote.
D) do not use the Internet to link buyers and sellers, thus employing brokers and trading floors.